Composite materials containing nanoparticles and their use in chromatography

ABSTRACT

Novel porous materials comprising nanoparticles, use in chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material are described by the instant invention. In particular, the disclosure describes porous inorganic/organic hybrid particles embedded with nanoparticles selected from oxides or nitrides of the following: silicon carbide, aluminum, diamond, cerium, carbon black, carbon nanotubes, zirconium, barium, cerium, cobalt, copper, europium, gadolinium, iron, nickel, samarium, silicon, silver, titanium, zinc, boron, and mixtures thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.12/936,782, filed Nov. 18, 2010, now U.S. Pat. No. 9,248,383, whichapplication is the U.S. national phase, pursuant to 35 U.S.C. § 371, ofPCT international application Ser. No. PCT/US2009/001893, filed Mar. 27,2009, designating the United States and published in English on Oct. 15,2009 as publication WO 2009/126207 A1, which claims priority to U.S.provisional application Ser. No. 61/043,230, filed Apr. 8, 2008. Theentire contents of the aforementioned patent applications areincorporated herein by this reference.

BACKGROUND OF THE INVENTION

Packing materials for liquid chromatography (LC) are generallyclassified into two types: organic materials, e.g., polydivinylbenzene,and inorganic materials typified by silica. Many organic materials arechemically stable against strongly alkaline and strongly acidic mobilephases, allowing flexibility in the choice of mobile phase pH. However,organic chromatographic materials generally result in columns with lowefficiency, leading to inadequate separation performance, particularlywith low molecular-weight analytes. Furthermore, many organicchromatographic materials not only lack the mechanical strength oftypical chromatographic silicas, but also shrink and swell when thecomposition of the mobile phase is changed.

Due in large part to these limitations, silica is the material mostwidely used in High Performance Liquid Chromatography (HPLC). The mostcommon applications employ silica that has been surface-derivatized withan organic functional group such as octadecyl (C₁₈), octyl (C₈), phenyl,amino, cyano, etc. As stationary phases for HPLC, these packingmaterials result in columns that have high efficiency and do not showevidence of shrinking or swelling.

To overcome the problems of residual silanol group activity (i.e.,increased retention, excessive peak tailing and irreversible adsorptionof some analytes) and hydrolytic instability of silica-based stationaryphases, many methods have been tried including use of ultrapure silica,carbonized silica, coating of the silica surface with polymericmaterials, endcapping free silanol groups with a short-chain reagentsuch as trimethylsilane, and the addition of suppressors such as aminesto the eluant. These approaches have not proven to be completelysatisfactory in practice.

One approach disclosed in U.S. Pat. No. 4,017,528 relates to a processfor preparing a “hybrid” silica, wherein an alkyl functionality iscoupled into both the skeleton structure and the surface of the silica.However, numerous problems remained prevalent with these materials,including packing problems associated with inhomogeneous morphology,irregular shapes and high concentrations of micropores that inhibitsolute mass transfer, resulting in poor peak shape and band broadening.

Although additional approaches have been used to circumvent theseproblems, there still remains a need for alternative materials thatsolve these problems as well as provide additional advantages, forexample, mechanical strength, increased column efficiency, andchromatographic selectivity.

SUMMARY OF THE INVENTION

The present invention provides composite materials, their use aschromatographic materials, e.g., particle and monolithic, and devicesand systems utilizing these materials. In particular, the compositematerials of the invention comprise nanoparticles distributed throughoutthe skeletal matrix of the polymer network. In certain embodiments, thematerials of the invention have increased mechanical strength andimproved thermal properties in addition to a pore geometry that iscapable of selective chromatographic separation.

Accordingly, one aspect of the invention provides a composite materialcomprising a nanoparticle dispersed within an inorganic or hybridmaterial derived from one or more components selected from the groupconsisting of an organic repeat unit; an organosilyl repeat unit; and aninorganic repeat unit. The material can be represented by the followingformulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the an organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C.

Another aspect of the invention provides a chromatographic materialcomprising a composite material, wherein the composite materialcomprises a nanoparticle dispersed within an inorganic or hybridmaterial derived from one or more components selected from the groupconsisting of an organic repeat unit; an organosilyl repeat unit; and aninorganic repeat unit, wherein the composite material is adapted for usein chromatography.

Further aspects of the present invention provide a separations device ora packed chromatography column comprising a chromatographic material ofthe present invention. In addition, the invention provides achromatography system comprising this packed chromatography column.

In yet another aspect, the invention provides a porous nanocompositeparticle comprising a composite material, wherein the composite materialcomprises a nanoparticle dispersed within an inorganic or hybridmaterial derived from one or more components selected from the groupconsisting of an organic repeat unit; an organosilyl repeat unit; and aninorganic repeat unit. The material may be represented by the followingformulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C.

Another aspect of the invention provides a high-pressure tolerantchromatography particle comprising a composite material, wherein thecomposite material comprises a nanoparticle within an inorganic orhybrid material derived from one or more components selected from thegroup consisting of an organic repeat unit; an organosilyl repeat unit;and an inorganic repeat unit. The particle of this embodiment is adaptedto substantially retain pore structure at fluid pressures greater than15,000 psi.

An additional aspect of the invention provides a thermally enhancedchromatography particle comprising a composite material, wherein thecomposite material comprises a nanoparticle within an inorganic orhybrid material derived from one or more components selected from thegroup consisting of an organic repeat unit; an organosilyl repeat unit;and an inorganic repeat unit. The particle of this embodiment is adaptedto improve thermal conduction of the composite material. In yet anotheraspect, the invention provides a method of preparing a compositematerial according to the present invention comprising dispersing one ormore types of nanoparticles within a polyoligomeric organosiloxane toform a dispersion mixture. The method further comprises condensing thedispersion mixture hydrolytically, such that a material according to thepresent invention is prepared.

Another aspect of the invention provides a chromatographic materialcomprising a composite material described herein, wherein the compositematerial comprises a nanoparticle dispersed within an inorganic orhybrid material derived from one or more components selected from thegroup consisting of an organic repeat unit; an organosilyl repeat unit;and an inorganic repeat unit, wherein the composite material is adaptedfor use in chromatography.

In another aspect, the invention provides a composite material describedherein, and prepared by any method described herein.

In yet another aspect, the invention provides a method of separatingcompounds using chromatography. The method comprises the steps ofapplying a mixture of compounds to a composite material described hereinunder appropriate chromatographic conditions, such that one or morecompounds in the mixture is separated from the mixture of compounds.

An additional aspect of the invention provides a kit comprising acomposite material described herein, and instructions for use inseparating a mixture of compounds in a chromatographic method.

Another aspect of the invention provides a method of performing aseparation comprising running a mixture of compounds through aseparations device comprising a composite material described herein,such that at least one compound is separated from the mixture.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 Sample 6k exhibited X-Ray Diffraction (XRD) evidence of twopolymorphs of TiO₂, Anatase (77.5% at 4.8 nm) and Brookite (22.5% at 6.6nm).

FIG. 2 is an SEM image/characterization of Sample 7a, and indicates theformation of highly spherical particles.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides unique composite materials that comprisenanoparticles distributed throughout the skeletal matrix of the polymernetwork. The selection and distribution of these nanoparticles affordsthe ability to control the physical characteristics of the resultingcomposite material, such as mechanical strength, thermal properties, andpore structure. Moreover, the present invention provides the use ofselected composites as chromatographic material, e.g., particle andmonolithic, separation devices that contain this material, as well assystems that employ such separation devices.

However, before further description of the present invention, and inorder that the invention may be more readily understood, certain termshave been first defined and collected here for convenience.

I. DEFINITIONS

The language, “adapted to” is used herein to describe the material ofthe present invention which is capable of or modified to have a certainnoted or recited property. For example, “adapted for use as achromatographic material,” is used to describe material of the inventionthat is modified to be more advantageous for chromatography, andincludes, but is not limited to properties such as pore size, surfacemodification, composition, nanoparticle size, and/or nanoparticlecomposition.

The language, “composite material” and the term “composite” are usedinterchangeably herein to describe the engineered materials of theinvention composed of one or more components described herein incombination with dispersed nanoparticles, wherein eachcomponent/nanoparticle remains separate and distinct on a macroscopiclevel within the finished structure. The composite material of thepresent invention is independent of form, and may be monolithic orparticulate in nature. Moreover, the short-hand convention used hereinto describe a composite material containing a dispersed nanoparticle,Np/(A)_(w)(B)_(x)(C)_(y), may be understood as follows: the symbolicrepresentation to the left of the slash mark represents the dispersednanoparticle, and the symbolic representations to the right of the slashmark represent the components that comprise the material that thenanoparticle (noted on the left of the slash mark) is dispersed within.In certain embodiments, the composite materials of the present inventionmay be nanocomposites, which are known to include, at least, forexample, nano/nano-type, intra-type, inter-type, and intra/inter-type.(Nanocomposites Science and Technology, edited by P. M. Ajayan, L. S.Schadler, P. V. Braun, Wiley-VCH (Weinheim, Germany), 2003)

The language “chromatographic material” is art-recognized, and describesa material that is particularly suited or adapted for use in thechromatographic separation of chemical mixtures. In certain embodiments,the material of the invention is adapted for use as a chromatographicmaterial.

The language “chromatographic separation” is art-recognized, anddescribes the process in which a chemical mixture carried by a liquid orgas is separated into its constituent ingredients as a result ofdifferential distribution of the solutes as they flow around or over astationary liquid or solid phase. For example, chromatographicseparations suitable for the materials of the present invention include,but are not limited to liquid chromatographic (including HPLC) methodssuch as normal-phase HPLC, RP-HPLC, HPLC, and size-exclusionchromatography (SEC), including gel permeation chromatography (GPC).Other suitable separations include additional HPLC methods and relatedliquid chromatographic techniques, including, e.g., ultra-performanceliquid chromatography (UPLC), fast performance liquid chromatography(FPLC) and the like.

The language “chromatographically-enhancing pore geometry” includes thegeometry of the pore configuration of certain materials described hereinthat have been found to enhance the chromatographic separation abilityof the material, e.g., as distinguished from other chromatographic mediain the art. For example, a geometry can be formed, selected orconstructed, and various properties and/or factors can be used todetermine whether the chromatographic separations ability of thematerial has been “enhanced”, e.g., as compared to a geometry known orconventionally used in the art. Examples of these factors include highseparation efficiency, longer column life, and high mass transferproperties (as evidenced by, e.g., reduced band spreading and good peakshape.) These properties can be measured or observed usingart-recognized techniques. For example, thechromatographically-enhancing pore geometry of certain particles of thepresent invention may be distinguished from the prior art particles bythe absence of “ink bottle” or “shell shaped” pore geometry ormorphology, both of which are undesirable because they, e.g., reducemass transfer rates, leading to lower efficiencies.

Chromatographically-enhancing pore geometry is found in compositematerial containing only a small population of micropores. A smallpopulation of micropores is achieved in material when all pores of adiameter of about <34 Å contribute less than about 110 m²/g to thespecific surface area of the material. Materials with such a lowmicropore surface area give chromatographic enhancements including highseparation efficiency and good mass transfer properties (as evidencedby, e.g., reduced band spreading and good peak shape). Micropore surfacearea is defined as the surface area in pores with diameters less than orequal to 34 Å, determined by multipoint nitrogen sorption analysis fromthe adsorption leg of the isotherm using the BJH method.

The terms “coalescing” and “coalesced” are intended to describe amaterial in which several individual components have become coherent toresult in one new component by an appropriate chemical or physicalprocess, e.g., heating. The term coalesced is meant to be distinguishedfrom a collection of individual particles in close physical proximity,e.g., in a bed formation, in which the end product comprises individualparticles.

The terms “dispersed” and “dispersion” are used herein to describe thedistribution of the nanoparticles within the composite materials of theinvention. The term “dispersed” includes the reasonably uniform orhomogeneous distribution, as well as heterogeneous distribution, each ofwhich may arise from the methods of preparation of the compositematerial as described herein (i.e., and in certain embodiments, may beexplained as a statistical distribution). In a particular embodiment,the dispersion is a reasonably homogeneous distribution.

The term “functionalized” is used herein to describe those materials ofthe present invention containing a functionalizing group.

The term “functionalizing group” includes organic functional groupswhich impart a certain chromatographic functionality to achromatographic stationary phase, including, e.g., octadecyl (C₁₈) orphenyl. Such functionalizing groups are present in, for example, surfacemodifiers such as disclosed herein which are attached to the basematerial, e.g., via derivatization or coating and later crosslinking,imparting the chemical character of the surface modifier to the basematerial. In an embodiment, such surface modifiers have the formulaZ_(a)(R′)_(b)Si—R, where Z═Cl, Br, I, C₁-C₅ alkoxy, dialkylamino, e.g.,dimethylamino, or trifluoromethanesulfonate; a and b are each an integerfrom 0 to 3 provided that a+b=3; R′ is a C₁-C₆ straight, cyclic orbranched alkyl group, and R is a functionalizing group. R′ may be, e.g.,methyl, ethyl, propyl, isopropyl, butyl, t-butyl, sec-butyl, pentyl,isopentyl, hexyl or cyclohexyl. In particular embodiments, R′ is methyl.

The term “hybrid”, i.e., as used in “hybrid material” is used herein asshorthand for the language “inorganic/organic hybrid material,” anddescribes material that possesses inorganic-based structures wherein anorganic functionality is integral to both the internal or “skeletal”inorganic structure as well as the hybrid material surface. Theinorganic portion of the hybrid material may be, e.g., alumina, silica,titanium or zirconium oxides, or ceramic material; in a preferredembodiment, the inorganic portion of the hybrid material is silica.Exemplary hybrid materials are shown in U.S. Pat. No. 4,017,528, thetext of which is incorporated herein by reference.

The language “inorganic repeat unit” describes a chemically distinctinorganic constituent or component of the composite materials of thepresent invention. In certain embodiments, the inorganic repeat unit isrepresented by the symbol “C,” which may comprise one or more differentforms of inorganic repeat unit and which may, for example, be selectedfrom the group consisting of alumina, silica, titanium, cerium, orzirconium oxides, and ceramic materials. In particular embodiments, theinorganic repeat unit may be

Moreover, it should be understood that the inorganic repeat unit isdescribed herein based on its form as incorporated into the matrix ofthe composite material, and therefore includes, for example,tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, andtetrabutoxysilane, e.g., tetramethoxysilane or tetraethoxysilane (whichare known surrogates for silica). For example, in one embodiment, theinorganic precursors are selected from the group consisting of theoxide, hydroxide, ethoxide, methoxide, propoxide, isopropoxide,butoxide, sec-butoxide, tert-butoxide, iso-butoxide, phenoxide,ethylhexyloxide, 2-methyl-2-butoxide, nonyloxide, isooctyloxide,glycolates, carboxylate, acetate, oxylate, nitrate, chlorides, amines,and mixtures thereof of silicon, titanium, zirconium, cerium oraluminum. In a particular embodiment, the inorganic precursors may beselected from the group consisting of one or more of methyl titaniumtriisopropoxide, methyl titanium triphenoxide, titaniumallylacetoacetatetriisopropoxide, titanium methacrylate triisopropoxide,titanium methacryloxyethylacetoacetate triisopropoxide,pentamethylcyclopentadienyl titanium trimethoxide,pentamethylcyclopentadienyl titanium trichloride, zirconiummethacryloxyethylacetoacetate tri-n-propoxide, cerium chloride, ceriumacetate, and cerium oxalate.

The term “monolith” is art-recognized and describes a porous,three-dimensional material having a continuous interconnected porestructure in a single piece. The term monolith is meant to bedistinguished from a collection of individual particles packed into abed formation, in which the end product comprises individual particles.In one embodiment, a monolith of the invention is prepared by castingprecursors into a mold of a desired shape. In another embodiment, themonolith comprises coalesced particles. In yet another embodiment, themonolith material may be used for chromatography, i.e., the monolith isa chromatographically useful material, e.g., a chromatographic column

The term “nanoparticle” is a microscopic particle/grain or microscopicmember of a powder/nanopowder with at least one dimension less thanabout 100 nm, e.g., a diameter or particle thickness of less than about100 nm (0.1 μm), which may be crystalline or noncrystalline.Nanoparticles have properties different from, and often superior tothose of conventional bulk materials including, for example, greaterstrength, hardness, ductility, sinterability, and greater reactivityamong others. Considerable scientific study continues to be devoted todetermining the properties of nanomaterials, small amounts of which havebeen synthesized (mainly as nano-size powders) by a number of processesincluding colloidal precipitation, mechanical grinding, and gas-phasenucleation and growth. Extensive reviews have documented recentdevelopments in nano-phase materials, and are incorporated herein byreference thereto: Gleiter, H. (1989) “Nano-crystalline materials,”Prog. Mater. Sci. 33:223-315 and Siegel, R. W. (1993) “Synthesis andproperties of nano-phase materials,” Mater. Sci. Eng. A168:189-197. Incertain embodiments, the nanoparticles comprise oxides or nitrides ofthe following: silicon carbide, aluminum, diamond, cerium, carbon black,carbon nanotubes, zirconium, barium, cerium, cobalt, copper, europium,gadolinium, iron, nickel, samarium, silicon, silver, titanium, zinc,boron, and mixtures thereof. In certain embodiments, the nanoparticlesof the present invention are selected from diamonds, zirconium oxide(amorphous, monoclinic, tetragonal and cubic forms), titanium oxide(amorphous, anatase, brookite and rutile forms), aluminum (amorphous,alpha, and gamma forms), and boronitride (cubic form). In particularembodiments, the nanoparticles of the present invention are selectedfrom nano-diamonds, silicon carbide, titanium dioxide (anatase form),cubic-boronitride, and any combination thereof. Moreover, in particularembodiments, the nanoparticles may be crystalline or amorphous. Inparticular embodiments, the nanoparticles are less than or equal to 100nm in diameter, e.g., less than or equal to 50 nm in diameter, e.g.,less than or equal to 20 nm in diameter.

Moreover, it should be understood that the nanoparticles that arecharacterized as dispersed within the composites of the invention areintended to describe exogenously added nanoparticles. This is incontrast to nanoparticles, or formations containing significantsimilarity with putative nanoparticles, that are capable of formation insitu, wherein, for example, macromolecular structures, such asparticles, may comprise an aggregation of these endogenously created.

Nanoparticles are of great scientific interest as they are effectively abridge between bulk materials and atomic or molecular structures. A bulkmaterial should have constant physical properties regardless of itssize, but at the nano-scale this is often not the case. Size-dependentproperties are observed such as quantum confinement in semiconductorparticles, surface plasmon resonance in some metal particles andsuperparamagnetism in magnetic materials.

The properties of materials change as their size approaches thenanoscale and as the percentage of atoms at the surface of a materialbecomes significant. For bulk materials larger than one micrometer thepercentage of atoms at the surface is minuscule relative to the totalnumber of atoms of the material. The interesting and sometimesunexpected properties of nanoparticles are partly due to the aspects ofthe surface of the material dominating the properties in lieu of thebulk properties. In certain embodiments, selection of the nanoparticleaffects the selectivity of the chromatographic material. For example,dispersion of TiO₂ or zirconium oxide could modify the surface charge,surface acidity, and therefore, the chromatographic selectivity.

The term “obtaining” as in obtaining a material, component or substanceis intended to include buying, synthesizing or otherwise acquiring thematerial. In certain embodiments of the invention, the methods comprisean additional step of obtaining the sample or reagents for use in themethods of the invention.

The language “organic repeat unit” describes a chemically distincthydrocarbon-based constituent or component of the composite materials ofthe present invention. The organic repeat unit may contain polymerizableor non-polymerizable moieties, and may be functionalized with a varietyof functional groups, e.g., polar or non-polar groups. In certainembodiments, the organic repeat unit is represented by the symbol “A,”which may comprise one or more different forms of organic repeat unitand which may, for example, be a substituted ethylene group. In aparticular embodiment, “A” may be selected from the group consisting of

wherein

k is an integer from 3-6;

m is an integer of from 1 to 20;

n and p are each independently integers of from 0 to 10;

Y is O, S(O)₀₋₂, NH, NR, NR₂ (when p is 0), NR₂ ⁺X⁻ (when p is not 0),or NR₃ ⁺X⁻ when p is 0, and where X⁻ is any anion (e.g., Cl⁻, OH⁻,carbonate),

Q is hydrogen, N(C₁₋₆alkyl)₃, N(C₁₋₆alkyl)₂(C₁₋₆alkyl-SO₃), or C(C₁₋₆hydroxy alkyl)₃, —CH(OH)CH₂(OH), OCH₂CH(OH)CH₂(OH),

and

each R, R₂, and R₃ is independently H or a C₁-C₁₀ alkyl group. Inparticular embodiments, each R may be independently hydrogen, methyl,ethyl, or propyl.

Moreover, in certain embodiments, repeat unit A may be derived from avariety of organic repeat unit reagents possessing one or morepolymerizable moieties, capable of undergoing polymerization, e.g., afree radical-mediated polymerization. Specifically, A repeat units maybe oligomerized or polymerized by a number of processes and mechanismsincluding, but not limited to, chain addition and step condensationprocesses, radical, anionic, cationic, ring-opening, group transfer,metathesis, and photochemical mechanisms.

The language “organosilyl repeat unit” describes a chemically distinctsilane-based constituent or component of the composite materials of thepresent invention that is functionalized with at least one organicmoiety directly bonded to the silicon atom, e.g., an organosiloxane(e.g., R′_(q)—Si(OR″)_(4-q), wherein R′ and R″ are lower alkyl moietiesand q is a positive number ranging from 0 to 4). The organic moiety maycontain polymerizable or non-polymerizable functional groups. In certainembodiments, the organic repeat unit is represented by the symbol “B,”which may comprise one or more different forms of organosilyl repeatunit and which may, for example, be an oxysilyl-substituted alkyl group.

In one embodiment, the organosilyl repeat unit has formula I:R⁶((R⁴)_(p)(R⁵)_(q)SiO_(t))_(m)  (I)

wherein,

R⁴ and R⁵ are each independently C₁-C₁₈ alkoxy, C₁-C₁₈ alkyl, C₁-C₁₈alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈heterocycloalkyl, C₅-C₁₈ aryl, C₅-C₁₈ aryloxy, or C₁-C₁₈ heteroaryl;

R⁶ is C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl,C₁-C₁₈ heterocycloalkyl, C₅-C₁₈ aryl, C₁-C₁₈ heteroaryl; or absent;wherein each R² is attached to two or more silicon atoms;

p and q are each independently 0.0 to 3.0,

t is 0.5, 1.0, or 1.5;

m is an integer from 1-20; wherein R⁴, R⁵ and R⁶ are optionallysubstituted; provided that: (1) when R⁶ is absent, m=1 and

${t = \frac{\left( {4 - \left( {p + q} \right)} \right)}{2}},$when p+q≤3; and

-   -   (2) when R⁶ is present, m=2-20 and

${t = \frac{\left( {3 - \left( {p + q} \right)} \right)}{2}},$

-   -    when p+q≤2.

In certain embodiments, R⁶ is absent, t=1.5 when p+q=1; or t=1 whenp+q=2. In other embodiments, R² is present, p=0, q is 0 or 1 and t=1.5when q=0; or t=1 when q=1.

In certain embodiments, R⁶ is absent. In other embodiments, R⁶ ispresent. In one embodiment of formula I in which R⁶ is present, theinvention provides a organosilyl repeat unit of formula I, wherein p is0, q is 0, t is 1.5, m is 2, and R⁶ is C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl,C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈ heterocycloalkyl, C₅-C₁₈ aryl,or C₁-C₁₈ heteroaryl; wherein each R⁶ is attached to two or more siliconatoms.

In other embodiments of formula I in which R⁶ is present, the inventionthe invention provides a organosilyl repeat unit of formula I, wherein qis 0, and R⁶ is C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈cycloalkyl, C₁-C₁₈ heterocycloalkyl, C₅-C₁₈ aryl, or C₁-C₁₈ heteroaryl;and wherein each R⁶ is attached to two or more silicon atoms. In afurther embodiment, p is 0, 1, or 2. In another further embodiment, t is1.0 or 1.5. In another embodiment, m is 1 or 2.

In another embodiment, the organosilyl repeat unit of the invention hasformula II:(R⁴)_(p)(R⁵)_(q)SiO_(t)  (II)wherein,

R⁴ and R⁵ are each independently C₁-C₁₈ alkoxy, C₁-C₁₈ alkyl, C₁-C₁₈alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈heterocycloalkyl, C₅-C₁₈ aryl, C₅-C₁₈ aryloxy, or C₁-C₁₈ heteroaryl;

p and q are each independently 0.0 to 3.0, provided that when p+q=1 thent=1.5; when p+q=2 then t=1; or when p+q=3 then t=0.5.

In yet another embodiment, the organosilyl repeat unit of the inventionhas formula III:R⁶((R⁵)_(r)SiO_(t))_(m)  (III)wherein,

R⁵ is C₁-C₁₈ alkoxy, C₁-C₁₈ alkyl, C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈ heterocycloalkyl, C₅-C₁₈ aryl, C₅-C₁₈aryloxy, or C₁-C₁₈ heteroaryl;

R⁶ is C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl,C₁-C₁₈ heterocycloalkyl, C₅-C₁₈ aryl, C₁-C₁₈ heteroaryl; or absent;wherein each R² is attached to two or more silicon atoms;

r is 0, 1 or 2, provided that when r=0 then t=1.5; when r=1 then t=1; orwhen r=2, then t=0.5; and

m is an integer from 1-20.

In various embodiments, the invention the invention provides aorganosilyl repeat unit of formulas I and II, wherein R is C₁-C₁₈alkoxy, C₁-C₁₈ alkyl, or C₁-C₁₈ alkyl. In various embodiments, theinvention the invention provides a organosilyl repeat unit of formulasI, II and III, wherein R¹ is C₁-C₁₈ alkoxy, C₁-C₁₈ alkyl, or C₁-C₁₈alkyl. In various embodiments, the invention the invention provides aorganosilyl repeat unit of formulas I and III, wherein R² is C₁-C₁₈alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈heterocycloalkyl, C₅-C₁₈ aryl, or C₁-C₁₈ heteroaryl.

In a particular embodiment, the organosilyl repeat unit may be selectedfrom the group consisting of

In a specific embodiment, the organosilyl repeat unit may be selectedfrom the group consisting of

For example, in one particular embodiment, the organosilyl repeat unitmay be selected from the group consisting of

For example, in one particular embodiment, the organosilyl repeat unitmay be selected from the group consisting of

wherein R, R¹ and R² are as defined previously; X is C₁-C₁₈ alkoxy orC₁-C₁₈ alkyl; and n is 1-8.

In certain embodiments, the monomer is 1,2-bis(triethoxysilyl)ethane:

In other embodiments, the monomer is 1,2-bis(methyldiethoxysilyl)ethane:

or 1,8-bis(triethoxysilyl)octane:

The language “repeat unit” as used herein, describes a monomer unit thatforms a constituent group of the composites described herein, incontrast to and distinct from a reactant that is used to prepare thecomposites of the present invention. For example, any reactant may beused that could arrive at the repeat units classified herein thatultimately form part of the constituent matrix of the composite.Moreover, the repeat units described herein (organic (A), organosilyl(B), and inorganic (C)) may be ordered as random, block, or acombination of random and block. A is an organic repeat unit which iscovalently bonded to one or more repeat units A or B via an organicbond. B is an organosilyl repeat unit which is bonded to one or morerepeat units B or C via an inorganic siloxane bond and which may befurther bonded to one or more repeat units A or B via an organic bond. Cis an inorganic repeat unit which is bonded to one or more repeat unitsB or C via an inorganic bond.

The language “surface modified” is used herein to describe the compositematerial of the present invention that possess both organic groups andsilanol groups which may additionally be substituted or derivatized witha surface modifier. “Surface modifiers” include (typically) organicfunctional groups which impart a certain chromatographic functionalityto a chromatographic stationary phase. Surface modifiers such asdisclosed herein are attached to the base material, e.g., viaderivatization or coating and later crosslinking, imparting the chemicalcharacter of the surface modifier to the base material. In oneembodiment, the organic groups of a hybrid material, e.g., particle,react to form an organic covalent bond with a surface modifier. Themodifiers can form an organic covalent bond to the material's organicgroup via a number of mechanisms well known in organic and polymerchemistry including but not limited to nucleophilic, electrophilic,cycloaddition, free-radical, carbene, nitrene, and carbocationreactions. Organic covalent bonds are defined to involve the formationof a covalent bond between the common elements of organic chemistryincluding but not limited to hydrogen, boron, carbon, nitrogen, oxygen,silicon, phosphorus, sulfur, and the halogens. In addition,carbon-silicon and carbon-oxygen-silicon bonds are defined as organiccovalent bonds, whereas silicon-oxygen-silicon bonds that are notdefined as organic covalent bonds. A variety of synthetictransformations are well known in the literature, see, e.g., March, J.Advanced Organic Chemistry, 3^(rd) Edition, Wiley, New York, 1985.

The language “substantially retaining column efficiency” is used hereinto describe the ability of a chromatographic material of a column toretain greater than 90% of its efficiency under a specified set ofconditions as compared with the efficiency prior to subjection to suchconditions.

The language “substantially retaining pore structure” is used herein todescribe the ability of the pore structure to retain its integrity undera specified set of conditions such that the material remainschromatographically useful.

II. MATERIALS OF THE INVENTION

A. Composites

Accordingly, one embodiment of the invention provides a compositematerial comprising a nanoparticle dispersed within an inorganic orhybrid material derived from one or more components selected from anorganic repeat unit; an organosilyl repeat unit; and an inorganic repeatunit. In certain embodiments, the material is represented by thefollowing formulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C. In one particular embodiment, the w is 0, e.g.,wherein x is 1 or x is 0.20 and y is 0.8. In another particularembodiment, x ranges from 0.04 to 1, e.g., 0.04 to 0.50.

As such, in certain embodiments of the invention, the material may berepresented by the following formulaNp/(B)_(x)(C)_(y)wherein:

x and y are each independently a positive number ranging from 0 to 1,such that w+x+y=1;

Np represents the nanoparticle;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C. In one particular embodiment, x is 1 or x is0.20 and y is 0.8. In another particular embodiment, x ranges from, 0 to1, e.g., 0.04 to 1, e.g., 0.04 to 0.50. Accordingly, in more specificembodiments, the material may be represented by either Np/B (e.g.,represented by one or more of formula I, II, or III, wherein R⁶ isethylene) or Np/C (e.g., wherein C is silica).

Exemplary embodiments of the composite material include, but are notlimited to

-   -   (B)y(C)z where B═O_(1.5)SiCH₂CH₂SiO_(1.5) and C═SiO₂, and y=0.2,        z=0.8 or when y is 0.2-1.0 and z is 0.8-0;    -   (B)y(C)z where B═O_(1.5)SiCH₂CH₂SiO_(1.5) and C═SiO₂, and y=0.2,        z=0.8 or when y is 0.2 and z is 0.8;    -   (B)y(C)z where B═O_(1.5)SiCH₂CH₂SiO_(1.5) and y=1 and z=0; and    -   (B)y(C)z where C═SiO₂ and z=1 and y=0.

For example, the present invention provides a chromatographic materialcomprising a composite material, e.g., a composite material describedherein, wherein the composite material comprises a nanoparticledispersed within an inorganic or hybrid material derived from one ormore components selected from the group consisting of an organic repeatunit; an organosilyl repeat unit; and an inorganic repeat unit, whereinthe composite material is adapted for use in chromatography. However, incertain embodiments, the chromatographic material is represented by thefollowing formulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C.

The nanoparticles of the invention may comprise, for example, oxides ornitrides of the following: silicon carbide, aluminum, diamond, cerium,carbon black, carbon nanotubes, zirconium, barium, cerium, cobalt,copper, europium, gadolinium, iron, nickel, samarium, silicon, silver,titanium, zinc, boron, and mixtures thereof. Moreover, in particularembodiments, the nanoparticles may be crystalline or amorphous. Inparticular embodiments, the nanoparticles are less than or equal to 200nm in diameter, e.g., less than or equal to 100 nm in diameter, e.g.,less than or equal to 50 nm in diameter, e.g., less than or equal to 20nm in diameter.

Interest in nanoparticles has grown over the last two decades because ofthe unusual properties that these particles possess, properties thatgenerally arise from the large surface area to volume ratios of theparticles, but also from their size. Once formed, the nanoparticles aredispersed within the composites of the invention to arrive at novelcomposite materials, e.g., of the formula described above. In particularembodiments, the nanoparticle is present in <20% by weight of thenanocomposite, e.g., the nanoparticle is present in <5% by weight of thenanocomposite.

The potential applications of composites made herein comprisingnanoparticles, include but are not limited to wear resistant coatings,thermal barrier coatings, ductile ceramics, new electronic and opticaldevices, and catalysts. Thus, composites comprising well knownnanoparticles, as well as nanoparticles that have been selected and/orprepared to achieve or produce a particular property in the resultingcomposite, are intended to be within the scope of the present invention.For example, nanoparticles that may be used herein include well-knownnanoparticles that have been made from metals (for example, Pd, Cu, Fe,Ag, Ni), intermetallics (for example, Al₅₂Ti₄₈), and metal oxides (forexample, TiO₂, Y₂O₃, ZnO, MgO, Al₂O₃). In certain embodiments, thenanoparticle is crystalline or amorphous.

The inorganic or hybrid material in which the nanoparticles aredispersed may be derived from one or more components selected from thegroup consisting of an organic repeat unit; an organosilyl repeat unit;and an inorganic repeat unit, wherein q is a positive number rangingfrom 0 to 4. In certain embodiments, at least one of repeat units A, B,or C is a mixture comprising two or more repeat units, e.g., the organicrepeat unit A may be comprised of two or more separate repeat units A′and A″ that may be collectively referred to as the A repeat unit.Moreover, the order of repeat units and nanoparticles may be random,block, or a combination thereof.

The resulting material may be a particle or a monolith. As such, in aspecific embodiment, the material is a particle, which may besubstantially spherical or non-spherical (e.g., ill-defined, granular,or agglomerated particles); wherein the particles may be crystalline oramorphous, with an average diameter of about 0.1 to 300 μm, e.g., about0.1 to 30 μm., e.g., about 0.1 to 20 μm. The pore structure of thematerial may be ordered, e.g., periodic, or disordered, e.g.,non-crystalline or amorphous, with an average pore diameter of about 20to 5000 Å, e.g., about 20 to 2000 Å, e.g., about 30 to 1000 Å, e.g.,about 60 to 400 Å, e.g., about 80 to 200 Å, e.g., about 90 to 150 Å. Thespecific surface area of the material is about 20 to 1100 m²/g, e.g.,about 80-500 m²/g or about 800-1100 m²/g, and has specific pore volumesof about 0.2 to 1.7 cm³/g, e.g., about 0.6 to 1.3 cm³/g. In certainembodiments, the material has a chromatographically enhancing poregeometry.

Moreover, in one embodiment, the invention provides porous, sphericalparticles that have pore structures which are either ordered ordisordered (e.g., non-crystalline or amorphous) molecular ordering, aswell as periodic pore structure. The controlled range of average porediameters of the particles of the invention provide a distribution ofchromatographically useful pore structure within a particle, allowingfor the use of the material for a wide range of chromatographicapplications, including separations of small molecules, peptides,proteins, nucleotides, polymeric molecules, and other macromolecules.

The present invention further provides that the material, e.g.,particles, may be surface modified by a surface modifier selected fromthe group consisting of an organic group surface modifier, a silanolgroup surface modifier, a polymeric coating surface modifier, and anycombination thereof. For example, the invention provides materials, suchas particles, wherein the particles have been surface modified by acombination of organic group and silanol group modification, wherein theparticles have been surface modified by silanol group modification, orwherein the particles have been surface modified by coating with apolymer, e.g., Sylgard®. In certain embodiments, the surface modifierhas the formula Z_(a)(R¹)_(b)Si—R², where Z═Cl, Br, I, C₁-C₅ alkoxy,dialkylamino or trifluoromethanesulfonate; a and b are each an integerfrom 0 to 3 provided that a+b=3; R¹ is a C₁-C₆ straight, cyclic orbranched alkyl group, and R² is a functionalizing group. In particularembodiments R¹ is selected from the group consisting of methyl, ethyl,propyl, isopropyl, butyl, t-butyl, sec-butyl, pentyl, isopentyl, hexyland cyclohexyl, e.g., methyl.

The functionalizing group R² may include of alkyl, alkenyl, alkynyl,aryl, cyano, amino, diol, nitro, cation or anion exchange groups, orembedded polar functionalities. Examples of suitable R functionalizinggroups include C₁-C₃₀ alkyl, including C₁-C₂₀, such as octyl (C₈),octadecyl (C₁₈), and triacontyl (C₃₀); alkaryl, e.g., C₁-C₄-phenyl;cyanoalkyl groups, e.g., cyanopropyl; diol groups, e.g., propyldiol;amino groups, e.g., aminopropyl; and alkyl or aryl groups with embeddedpolar functionalities, e.g., carbamate functionalities such as disclosedin U.S. Pat. No. 5,374,755, the text of which is incorporated herein byreference. Such groups include those of the general formula

wherein l, m, o, r, and s are 0 or 1, n is 0, 1, 2 or 3 p is 0, 1, 2, 3or 4 and q is an integer from 0 to 19; R₃ is selected from the groupconsisting of hydrogen, alkyl, cyano and phenyl; and Z, R′, a and b aredefined as above. In particular embodiments, the carbamate functionalityhas the general structure indicated below:

wherein R⁵ may be, e.g., cyanoalkyl, t-butyl, butyl, octyl, dodecyl,tetradecyl, octadecyl, or benzyl. In specific embodiments, R⁵ is octyl,dodecyl, or octadecyl. In a particular embodiment, the surface modifiermay be an organotrihalosilane, such as octyltrichlorosilane oroctadecyltrichlorosilane, or a halopolyorganosilane, such asoctyldimethylchlorosilane or octadecyldimethylchlorosilane.

In another embodiment, the organic groups and silanol groups of thematerial are both surface modified or derivatized. In anotherembodiment, the particles are surface modified by coating with apolymer. In certain embodiments, surface modification by coating with apolymer is used in conjunction with silanol group modification, organicgroup modification, or both silanol and organic group modification.

Polymer coatings are also known in the literature and may be providedgenerally by polymerization or polycondensation of physisorbed repeatunits onto the surface of the materials of the present invention withoutchemical bonding of the polymer layer to the support (type I),polymerization or polycondensation of physisorbed repeat units onto thesurface with chemical bonding of the polymer layer to the support (typeII), immobilization of physisorbed prepolymers to the support (typeIII), and chemisorption of presynthesized polymers onto the surface ofthe support (type IV). see, e.g., Hanson et al., J. Chromat. A656 (1993)369-380, the text of which is incorporated herein by reference. As notedabove, coating the material of the invention with a polymer may be usedin conjunction with various surface modifications described in theinvention.

The term “aliphatic group” includes organic compounds characterized bystraight or branched chains, typically having between 1 and 22 carbonatoms. Aliphatic groups include alkyl groups, alkenyl groups and alkynylgroups. In complex structures, the chains can be branched orcross-linked. Alkyl groups include saturated hydrocarbons having one ormore carbon atoms, including straight-chain alkyl groups andbranched-chain alkyl groups. Such hydrocarbon moieties may besubstituted on one or more carbons with, for example, a halogen, ahydroxyl, a thiol, an amino, an alkoxy, an alkylcarboxy, an alkylthio,or a nitro group. Unless the number of carbons is otherwise specified,“lower aliphatic” as used herein means an aliphatic group, as definedabove (e.g., lower alkyl, lower alkenyl, lower alkynyl), but having fromone to six carbon atoms. Representative of such lower aliphatic groups,e.g., lower alkyl groups, are methyl, ethyl, n-propyl, isopropyl,2-chloropropyl, n-butyl, sec-butyl, 2-aminobutyl, isobutyl, tert-butyl,3-thiopentyl, and the like. As used herein, the term “nitro” means —NO₂;the term “halogen” designates —F, —Cl, —Br or —I; the term “thiol” meansSH; and the term “hydroxyl” means —OH. Thus, the term “alkylamino” asused herein means an alkyl group, as defined above, having an aminogroup attached thereto. Suitable alkylamino groups include groups having1 to about 12 carbon atoms, preferably from 1 to about 6 carbon atoms.The term “alkylthio” refers to an alkyl group, as defined above, havinga sulfhydryl group attached thereto. Suitable alkylthio groups includegroups having 1 to about 12 carbon atoms, preferably from 1 to about 6carbon atoms. The term “alkylcarboxyl” as used herein means an alkylgroup, as defined above, having a carboxyl group attached thereto. Theterm “alkoxy” as used herein means an alkyl group, as defined above,having an oxygen atom attached thereto. Representative alkoxy groupsinclude groups having 1 to about 12 carbon atoms, preferably 1 to about6 carbon atoms, e.g., methoxy, ethoxy, propoxy, tert-butoxy and thelike. The terms “alkenyl” and “alkynyl” refer to unsaturated aliphaticgroups analogous to alkyls, but which contain at least one double ortriple bond respectively. Suitable alkenyl and alkynyl groups includegroups having 2 to about 12 carbon atoms, preferably from 1 to about 6carbon atoms.

The term “alicyclic group” includes closed ring structures of three ormore carbon atoms. Alicyclic groups include cycloparaffins or naphtheneswhich are saturated cyclic hydrocarbons, cycloolefins which areunsaturated with two or more double bonds, and cycloacetylenes whichhave a triple bond. They do not include aromatic groups. Examples ofcycloparaffins include cyclopropane, cyclohexane, and cyclopentane.Examples of cycloolefins include cyclopentadiene and cyclooctatetraene.Alicyclic groups also include fused ring structures and substitutedalicyclic groups such as alkyl substituted alicyclic groups. In theinstance of the alicyclics such substituents can further comprise alower alkyl, a lower alkenyl, a lower alkoxy, a lower alkylthio, a loweralkylamino, a lower alkylcarboxyl, a nitro, a hydroxyl, —CF₃, —CN, orthe like.

The term “heterocyclic group” includes closed ring structures in whichone or more of the atoms in the ring is an element other than carbon,for example, nitrogen, sulfur, or oxygen. Heterocyclic groups can besaturated or unsaturated and heterocyclic groups such as pyrrole andfuran can have aromatic character. They include fused ring structuressuch as quinoline and isoquinoline. Other examples of heterocyclicgroups include pyridine and purine. Heterocyclic groups can also besubstituted at one or more constituent atoms with, for example, ahalogen, a lower alkyl, a lower alkenyl, a lower alkoxy, a loweralkylthio, a lower alkylamino, a lower alkylcarboxyl, a nitro, ahydroxyl, —CF₃, —CN, or the like. Suitable heteroaromatic andheteroalicyclic groups generally will have 1 to 3 separate or fusedrings with 3 to about 8 members per ring and one or more N, O or Satoms, e.g. coumarinyl, quinolinyl, pyridyl, pyrazinyl, pyrimidyl,furyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, indolyl,benzofuranyl, benzothiazolyl, tetrahydrofuranyl, tetrahydropyranyl,piperidinyl, morpholino and pyrrolidinyl.

The term “aromatic group” includes unsaturated cyclic hydrocarbonscontaining one or more rings. Aromatic groups include 5- and 6-memberedsingle-ring groups which may include from zero to four heteroatoms, forexample, benzene, pyrrole, furan, thiophene, imidazole, oxazole,thiazole, triazole, pyrazole, pyridine, pyrazine, pyridazine andpyrimidine, and the like. The aromatic ring may be substituted at one ormore ring positions with, for example, a halogen, a lower alkyl, a loweralkenyl, a lower alkoxy, a lower alkylthio, a lower alkylamino, a loweralkylcarboxyl, a nitro, a hydroxyl, —CF₃, —CN, or the like.

The term “alkyl” includes saturated aliphatic groups, includingstraight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl(alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkylsubstituted alkyl groups. In certain embodiments, a straight chain orbranched chain alkyl has 30 or fewer carbon atoms in its backbone, e.g.,C₁-C₃₀ for straight chain or C₃-C₃₀ for branched chain. In certainembodiments, a straight chain or branched chain alkyl has 20 or fewercarbon atoms in its backbone, e.g., C₁-C₂₀ for straight chain or C₃-C₂₀for branched chain, and more preferably 18 or fewer. Likewise, preferredcycloalkyls have from 4-10 carbon atoms in their ring structure, andmore preferably have 4-7 carbon atoms in the ring structure. The term“lower alkyl” refers to alkyl groups having from 1 to 6 carbons in thechain, and to cycloalkyls having from 3 to 6 carbons in the ringstructure.

Moreover, the term “alkyl” (including “lower alkyl”) as used throughoutthe specification and claims includes both “unsubstituted alkyls” and“substituted alkyls”, the latter of which refers to alkyl moietieshaving substituents replacing a hydrogen on one or more carbons of thehydrocarbon backbone. Such substituents can include, for example,halogen, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkoxycarbonyl,aminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate, phosphonato,phosphinato, cyano, amino (including alkyl amino, dialkylamino,arylamino, diarylamino, and alkylarylamino), acylamino (includingalkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), amidino,imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfate,sulfonato, sulfamoyl, sulfonamido, nitro, trifluoromethyl, cyano, azido,heterocyclyl, aralkyl, or an aromatic or heteroaromatic moiety. It willbe understood by those skilled in the art that the moieties substitutedon the hydrocarbon chain can themselves be substituted, if appropriate.Cycloalkyls can be further substituted, e.g., with the substituentsdescribed above. An “aralkyl” moiety is an alkyl substituted with anaryl, e.g., having 1 to 3 separate or fused rings and from 6 to about 18carbon ring atoms, e.g., phenylmethyl (benzyl).

The term “aryl” includes 5- and 6-membered single-ring aromatic groupsthat may include from zero to four heteroatoms, for example,unsubstituted or substituted benzene, pyrrole, furan, thiophene,imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine,pyridazine and pyrimidine, and the like. Aryl groups also includepolycyclic fused aromatic groups such as naphthyl, quinolyl, indolyl,and the like. The aromatic ring can be substituted at one or more ringpositions with such substituents, e.g., as described above for alkylgroups. Suitable aryl groups include unsubstituted and substitutedphenyl groups. The term “aryloxy” as used herein means an aryl group, asdefined above, having an oxygen atom attached thereto. The term“aralkoxy” as used herein means an aralkyl group, as defined above,having an oxygen atom attached thereto. Suitable aralkoxy groups have 1to 3 separate or fused rings and from 6 to about 18 carbon ring atoms,e.g., O-benzyl.

The term “amino,” as used herein, refers to an unsubstituted orsubstituted moiety of the formula —NR_(a)R_(b), in which R_(a) and R_(b)are each independently hydrogen, alkyl, aryl, or heterocyclyl, or R_(a)and R_(b), taken together with the nitrogen atom to which they areattached, form a cyclic moiety having from 3 to 8 atoms in the ring.Thus, the term “amino” includes cyclic amino moieties such aspiperidinyl or pyrrolidinyl groups, unless otherwise stated. An“amino-substituted amino group” refers to an amino group in which atleast one of R_(a) and R_(b), is further substituted with an aminogroup.

Without wishing to be bound by theory, the materials of the inventionare believed to have a polymer matrix that is substantially void-free,and which are formed by embedding nanoparticles in gaps between formedor forming polymers. Upon incorporation of the nanoparticles, a matrixembedding individual polymers results, where the matrix is substantiallyfree of voids and defects. As such, an advantageous feature of thepresent invention involves the ability to impregnate gaps betweenindividual polymers with nanoparticles.

The materials and particles of the instant invention provide forimprovements in thermal properties similar to those achieved by mixedbed packings with micro sized particles, but with similar loadingcapacities as unmodified porous packed bed materials. The materials andparticles of the instant invention are distinct from surface metallizedparticles in that the materials possess similar chromatographic runparameters (i.e., selectivity, retentivity, mobile phase compositions)as silica or hybrid particles without the requirement of significantchanges in mobile phase composition or chromatographic run conditions.Additionally, the materials and particles of the instant invention aredistinct from hybrid particles that co-condense a soluble metalprecursor within a partial condensation reaction with anorganofunctional silane or tetraalkoxysilane, in that the nanoparticlesare distributed throughout the skeletal wall matrix as individualnanoparticles homogenously or heterogeneously within the polymernetwork. Moreover, the composites described herein comprisingnanoparticles are prepared without the need for the high temperaturesordinarily used to change the crystal structure of nanocomposites. Forexample TiO₂ from metal alkoxide formation is normally amorphous at roomtemperature. Temperature 300-500° C. can be used to anneal this materialand start to form the anatase structure. At temperatures >600° C. arutile crystal form can start to develop. However, in a typical BCC′hybrid with amorphous TiO₂, thermal decomposition of the hybrid groupwould be observed when heat is used to form anatase or rutile. The sameis true for diamonds (formed from very high temperatures, pressures andtime, or from explosions) and cubic boronitride. The novel approachdescribed herein, of adding nanoparticles, is the only way of addingthese type of materials without degrading the hybrid material.

The thermal property improvement goes to the excellent thermalconduction of certain embodiments of the composites of the presentinvention, e.g., nanoparticle diamonds. For example, without wishing tobe bound by theory, it is believed that diamonds help with thermaltransfer from the column to the walls, reducing heat gradients on columnthat can lower performance of columns with smaller particles or widercolumn diameters.

In one embodiment, the material, e.g., porous material, is provided bycontrolling the inorganic or hybrid component content and nanoparticlecontent of the material. An optimal blend for a particular porousmaterial can depend on the size, viscosity, temperature of the emulsionand/or the presence of other additives such as surfactants orstabilizers. Stabilizers may be added to the emulsion to extend the timeof stability and are usually polymers that are soluble in the emulsionand thicken the emulsion. In certain embodiments, the inorganic orhybrid component content of the porous materials of the presentinvention ranges from about 25% to about 99.999%, depending on thepresence of additives. In other embodiments, the inorganic or hybridcomponent content may range from about 25% to about 50%, or from about25% to about 35%. In other embodiments, the inorganic or hybridcomponent content ranges from about 40% to about 85%. In certainembodiments, the inorganic or hybrid component content ranges from about50% to about 75%. In other embodiments, the inorganic or hybridcomponent content ranges from about 90% to about 99.9%. In certainembodiments, the inorganic or hybrid component content ranges from about95% to about 99%. The total amount of nanoparticle may range from about0.1% by weight to about 20% by weight, preferably from about 1.0% byweight to about 10% by weight, based upon the weight of the porousmaterial.

In certain embodiments, the material of the invention, e.g., prepared bythe methods of the invention, having a chromatographically-enhancingpore geometry generally have a specific surface area, as measured by N₂sorption analysis, of about 50 to 800 m²/g, particularly about 75 to 600m²/g, more particularly about 100 to 200 m²/g. The specific pore volumeof the particles is generally about 0.25 to 1.5 cm³/g, particularlyabout 0.4 to 1.2 cm³/g, more particularly about 0.5 to 1.0 cm³/g. Thematerials of the invention possessing a chromatographically-enhancingpore geometry have an average pore diameter of generally about 50 to 500Å, particularly about 60 to 500 Å, more particularly about 100 to 300 Å.The micropore surface area is less than about 110 m²/g, particularlyless than about 105 m²/g, more particularly less than about 80 m²/g, andstill more particularly less than about 50 m²/g.

III. APPLICATIONS OF THE MATERIALS OF THE INVENTION

The materials of the present invention, among other noted applications,may at least be useful in commercial applications such as packings forchromatography (UPLC, HPLC) columns, chromatographic cartridges, platesor specialized biomolecule separation kits, sequestering reagents, solidsupports for combinatorial chemistry, solid supports foroligosaccharide, polypeptides, and/or oligonucleotide synthesis, solidsupported biological assays, capillary biological assay devices for massspectrometry, templates for controlled large pore polymer films,capillary chromatography, electrokinetic pump packing materials, polymeradditives, catalyst supports, and packing materials for microchipseparation devices.

In particular, the porous material. e.g., particles, have a wide varietyof end uses in the separation sciences, such as packing materials forchromatographic columns wherein such columns may have improved stabilityto alkaline mobile phases and reduced peak tailing for basic analytes,thin layer chromatographic (TLC) plates, solid phase extraction devices,filtration membranes, microtiter plates, scavenger resins, solid phaseorganic synthesis supports, and the like having a stationary phase whichincludes porous inorganic/organic hybrid particles having achromatographically-enhancing pore geometry. The stationary phase may beintroduced by packing, coating, impregnation, etc., depending on therequirements of the particular device. In a particular embodiment, thechromatographic device is a packed chromatographic column, such ascommonly used in HPLC and UPLC.

As such, one embodiment of the invention provides chromatographicmaterial provided in the invention comprises a composite material,wherein the composite material comprises a nanoparticle dispersed withinan inorganic or hybrid material derived from one or more componentsselected from the group consisting of an organic repeat unit; anorganosilyl repeat unit; and an inorganic repeat unit, wherein q is apositive number ranging from 0 to 4. In certain embodiments, thechromatographic material is represented by the following formulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C. In particular embodiments, the material isadapted for use in a particular separation device. For example, thematerial may be adapted for use as a liquid chromatography stationaryphase; a sequestering reagent; a solid support for combinatorialchemistry; a solid support for oligosaccharide, polypeptide, oroligonucleotide synthesis; a solid support for a biological assay; acapillary biological assay device for mass spectrometry; a template fora controlled large pore polymer film; a capillary chromatographystationary phase; an electrokinetic pump packing material; a polymeradditive; a catalyst; or a packing material for a microchip separationdevice. In one specific embodiment, the material is adapted for use asan HPLC or UPLC stationary phase.

As such, one embodiment of the invention provides a separations devicecomprising a material of the invention, e.g., a chromatographic materialof the invention. For example, the device may be selected fromchromatographic columns, thin layer plates, solid phase extractiondevices, filtration membranes, sample cleanup devices, and microtiterplates.

Another embodiment of the invention provides a packed chromatographycolumn containing a material of the invention, e.g., a chromatographicmaterial of the invention, as well as a chromatography system comprisingthis packed chromatography column.

In another embodiment the invention provides a porous nanocompositeparticle, e.g., a particle that is approximately spherical, comprising awithin an inorganic or hybrid material derived from one or morecomponents selected from the group consisting of an organic repeat unit;an organosilyl repeat unit; and an inorganic repeat unit, and whereinthe material is represented by the following formulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

q is a positive number ranging from 0 to 4;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C. The particles, as noted above, may haveparticularly advantageous properties, including, but not limited toenhanced pressure tolerance (i.e., possessing a higher mechanicalstrength) and/or thermally enhanced. In particular embodiments, theparticles prepared have higher mechanical strength and do not swell inorganic solvents.

In this manner, another embodiment of the invention provides ahigh-pressure tolerant chromatography particle comprising a compositematerial, wherein the composite material comprises a nanoparticle withinan inorganic or hybrid material derived from one or more componentsselected from the group consisting of an organic repeat unit; anorganosilyl repeat unit; and an inorganic repeat unit, and wherein theparticle is capable of substantially retaining pore structure at fluidpressures greater than 15,000 psi, e.g., fluid pressures ranging fromabout 20,000 psi to about 100,000 psi. As such, in certain embodimentsthe particle is capable of use in UPLC. Moreover, in an additionalembodiment the invention provides an enhanced performance UPLC column,e.g., having an inner diameter of less than 2 microns, packed with theseparticles. The language “enhanced performance” describes acharacteristic of a UPLC column of having improved thermalcharacteristics at loading capacities that are equal to known mixed bedpacked columns useful for UPLC.

In a further embodiment, the invention provides a thermally enhancedchromatography particle comprising a composite material, wherein thecomposite material comprises a nanoparticle within an inorganic orhybrid material derived from one or more components selected from thegroup consisting of an organic repeat unit; an organosilyl repeat unit;and an inorganic repeat unit, and wherein the particle is adapted toimprove thermal conduction of the composite material. In certainembodiments, the composite material is adapted to substantially retaincolumn efficiency at temperatures greater than 200° C.

The thermally enhanced particles or the high-pressure tolerant particlesmay, in certain embodiments, comprise particles less than 2 μm indiameter. Moreover, the nanoparticle may be a substance which comprisesone or more moieties selected from the group consisting of siliconcarbide, aluminum, diamond, cerium, carbon black, carbon nanotubes,zirconium, barium, cerium, cobalt, copper, europium, gadolinium, iron,nickel, samarium, silicon, silver, titanium, zinc, boron, oxidesthereof, and nitrides thereof. In particular embodiments the compositematerial is represented by the following formulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C. In additional particular embodiments, theporosity of particle is greater than 0.3 cc/g, e.g., greater than 1.0cc/g, e.g., ranging from about 1.0 cc/g to 2.0 cc/g. In a specificembodiment, the porosity of particle ranges from 0.3-0.8 cc/g.

In yet another aspect, the invention provides a porous nanocompositemonolith comprising a composite material, wherein the composite materialcomprises a nanoparticle dispersed within an inorganic or hybridmaterial derived from one or more components selected from the groupconsisting of an organic repeat unit; an organosilyl repeat unit; and aninorganic repeat unit. The material may be represented by the followingformulaNp/(A)_(w)(B)_(x)(C)_(y)wherein:

w, x, and y are each independently a positive number ranging from 0 to1, such that w+x+y=1;

Np represents the nanoparticle;

A represents the organic repeat unit;

B represents the organosilyl repeat unit;

C represents the inorganic repeat unit; and

wherein each repeat unit is covalently bonded to one or more separaterepeat units A, B, or C.

In yet embodiment, the invention provides a method of separatingcompounds using chromatography. The method comprises the steps ofapplying a mixture of compounds to a composite material described hereinunder appropriate chromatographic conditions, such that one or morecompounds in the mixture is separated from the mixture of compounds.Application of the mixture of compounds may be accomplished by anyart-recognized technique. In particular embodiments, the mixture ofcompounds is selected based on the particular separation properties ofthe composite material used for chromatography, e.g., polarity,hydrophobicity, hydrophilicity, or particular derivatization. In certainembodiments, the method further comprises obtaining the compositematerial. In certain embodiments, the method further comprises the stepof preparing a separations device containing the composite material. Inspecific embodiments, the mixture of compounds is applied to aseparations device comprising the composite material, and suchseparations device may include, but is not limited to chromatographiccolumns, thin layer plates, solid phase extraction devices, filtrationmembranes, sample cleanup devices, and microtiter plates.

Another embodiment of the invention provides a method of performing aseparation comprising running a mixture of compounds through aseparations device comprising a composite material described herein,such that at least one compound is separated from the mixture. Themixture of compounds may be derived from any source, e.g., biologicallyor synthetically produced. In certain embodiments, the separatedcompound is a compound which has been significantly enriched orcompletely separated. Moreover, the term “running” is an art-recognizedterm that indicates the process of passing the compound mixture throughchromatographic media stationary phase using mobile phase.

An additional embodiment of the invention provides a kit comprising acomposite material described herein, and instructions for use inseparating a mixture of compounds in a chromatographic method. Incertain embodiments, the instructions provide instruction for use of thecomposite material in a method of separating compounds usingchromatography, e.g., as described herein. In particular embodiments,the kit further comprises a separations device.

VI. METHOD OF PREPARATION

In an additional embodiment, the present invention provides methods ofpreparing a composite materials of the invention. These methods comprisedispersing one or more types of nanoparticles within a polyoligomericorganosiloxane to form a dispersion mixture, and condensing thedispersion mixture hydrolytically, such that a material of the inventionis prepared. In certain embodiments, the polyoligomeric organosiloxanesis formed from the partial condensation of one or more componentsselected from the group consisting of an organic repeat unit; anorganosilyl repeat unit; an inorganic repeat unit; and any combinationthereof. In particular embodiments, the invention provides a porousmaterial, e.g., particle, which has been synthesized by the hydrolyticcondensation of one or more nanoparticles (<20 wt %) dispersed withinpolyoligomeric organosiloxanes, which is comprised of a partiallycondensed organofunctional silane, a tetraalkoxysilane, a mixture of twoor more organofunctional silanes, or a mixture of one or moreorganofunctional silanes, with a tetraalkoxysilane, e.g.,tetraethoxysilane or tetramethoxysilane. In certain embodiments, thematerial that is prepared has a chromatographically enhancing poregeometry.

In certain embodiments, the polyoligomeric organosiloxane (POS) ispre-made and the dispersion mixture is prepared by addition of thenanoparticles to the polyoligomeric organosiloxane with agitation of theresulting mixture to form the dispersion mixture, e.g., see Example 3.The agitation may occur by using magnetic mixing, mechanical mixing,rotor-stator mixing, or sonication. Centrifugation or filtration may beused to remove large nanoparticle or aggregated materials.

In certain alternate embodiments, the polyoligomeric organosiloxane ispre-made and the dispersion mixture is prepared by addition of a slurryof the nanoparticles (e.g., wherein the slurry of nanoparticles isselected from the group consisting of an aqueous slurry, an alcoholslurry, an ether slurry, or a combination thereof) to the polyoligomericorganosiloxane with agitation of the resulting mixture to form thedispersion mixture, e.g., see Example 4. In particular embodiments, thecosolvent of the slurry is removed (e.g., water, alcohol or ethersolution) by atmospheric or vacuum distillation to produce a Np/POS. Inother particular embodiments, the cosolvent is not removed, forming adispersion of nanoparticles in a POS/cosolvent (e.g., water, alcohol, orether). The agitation may occur by using magnetic mixing, mechanicalmixing, rotor-stator mixing, or sonication. Centrifugation or filtrationmay be used to remove large nanoparticle or aggregated materials.

In certain additional alternate embodiments, the dispersion mixture isprepared by addition of the nanoparticles to the condensation reactionthat forms the polyoligomeric organosiloxane with agitation of theresulting mixture to form the dispersion mixture, e.g., see Example 2.The agitation may occur by using magnetic mixing, mechanical mixing,rotor-stator mixing, or sonication. Centrifugation or filtration may beused to remove large nanoparticle or aggregated materials.

For example, the organic repeat unit is incorporated into the materialby reaction of an organic olefin repeat unit selected from the groupconsisting of divinylbenzene, styrene, vinylbenzylchloride, ethyleneglycol dimethacrylate, 1-vinyl-2-pyrrolidinone, N-vinylcaprolactam,tert-butylmethacrylate, acrylamide, methacrylamide,N,N′-(1,2-dihydroxyethylene)bisacrylamide, N,N′-ethylenebisacrylamide,N,N′-methylenebisacrylamide, butyl acrylate, ethyl acrylate, methylacrylate, 2-(acryloxy)-2-hydroxypropyl methacrylate,3-(acryloxy)-2-hydroxypropyl methacrylate, trimethylolpropanetriacrylate, trimethylolpropane ethoxylate triacrylate,tris[(2-acryloyloxy)ethyl] isocyanurate, acrylonitrile,methacrylonitrile, itaconic acid, methacrylic acid,trimethylsilylmethacrylate, N-[tris(hydroxymethyl) methyl]acrylamide,(3-acrylamidopropyl)trimethylammonium chloride,[3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxideinner salt,

Exemplary organosilyl repeat units that may be used in this approachincludes (but is not limited to); bis(triethoxysilyl)ethane;bis(triethoxylsilyl)octane; bis(methyldiethoxysilyl)ethane;bis(triethoxysilyl)ethene; bis(trimethoxysilylethyl)benzene;ethyltriethoxysilane; diethyldiethoxysilane;mercaptopropyltriethoxysilane; methyltriethoxysilane;vinyltriethoxysilane; hexyltriethoxysilane; chloropropyltriethoxysilane;phenylethyltrimethoxysilane; octadecyltrimethoxysilane;octyltrimethoxysilane; 3,3.3-trifluoropropyltrimethoxysilane; and3-cyanobutyltriethoxysilane. The use of reactive organoalkoxysilanesthat have been shown to react by protodesilylation, deprotection, ordecompose may also be useful in introducing porosity into hybridparticles. A list of organoalkoxysilanes that may protodesilylate,deprotect or decompose to introduce porosity into hybrid particlesincludes (but is not limited to); phenyltriethoxysilane;methacryloxypropyltrimethoxysilane; acetyloxyethyltrimethoxysilane,chloroethyltriethoxysilane, and fluorotriethoxysilane. The use of alkenesubstituted organoalkoxysilanes that may be used in this approach toform both organic bonds (e.g., free radical polymerization) andinorganic siloxane bonds within the particle framework includes (but isnot limited to); methacryloxypropyl trimethoxysilane,methacryloxypropyltriethoxysilane, vinyltriethoxysilane,vinyltrimethoxysilane, N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, (3-acryloxypropyl) trimethoxysilane,O-(methacryloxyethyl)-N-(triethoxysilylpropyl)urethane,N-(3-methacryloxy-2-hydroxypropyl)-3-aminopropyl triethoxysilane,methacryloxy methyltriethoxysilane, methacryloxymethyl trimethoxysilane,methacryloxypropy methyldiethoxysilane,methacryloxypropylmethyldimethoxysilane, methacryl oxypropyltris(methoxyethoxy)silane, 3-(N-styrylmethyl-2-aminoethylamino)propyltrimethoxysilane hydrochloride,

wherein

each R is independently H or a C₁-C₁₀ alkyl group and wherein R′ isindependently H or a C₁-C₁₀ alkyl group. In specific embodiments, each Ris independently hydrogen, methyl, ethyl, or propyl. In another specificembodiment, all of the R groups are identical and are selected from thegroup consisting of hydrogen, methyl, ethyl, or propyl.

Nanoparticles of the present invention may be commercially available ormay be prepared using well-known techniques. Nanoparticle formationtechniques include chemical and physical vapor deposition; mechanicalattrition; gas phase pyrolysis and condensation; electrodeposition;cryochemical synthesis; laser pyrolysis; gel synthesis; and altering ofmolecular ordering/crystallinity of a material through the use of, forexample, hydrothermal or heat treatment. For example, in attrition,macro or micro scale particles are ground in a ball mill, a planetaryball mill, or other size reducing mechanism. The resulting particles areair classified to recover nanoparticles. In pyrolysis, an organicprecursor (liquid or gas) is forced through an orifice at high pressureand burned. The resulting ash is air classified to recover oxidenanoparticle.

A thermal plasma can also deliver the energy necessary to causeevaporation of small micrometre size particles. The thermal plasmatemperatures are in the order of 10000 K, so that solid powder easilyevaporates. Nanoparticles are formed upon cooling while exiting theplasma region. The main types of the thermal plasmas torches used toproduce nanoparticles are dc plasma jet, dc arc plasma and radiofrequency (RF) induction plasmas. In the arc plasma reactors, the energynecessary for evaporation and reaction is provided by an electric arcwhich forms between the anode and the cathode. For example, silica sandcan be vaporized with an arc plasma at atmospheric pressure. Theresulting mixture of plasma gas and silica vapour can be rapidly cooledby quenching with oxygen, thus ensuring the quality of the fumed silicaproduced. In RF induction plasma torches, energy coupling to the plasmais accomplished through the electromagnetic field generated by theinduction coil. The plasma gas does not come in contact with electrodes,thus eliminating possible sources of contamination and allowing theoperation of such plasma torches with a wide range of gases includinginert, reducing, oxidizing and other corrosive atmospheres. The workingfrequency is typically between 200 kHz and 40 MHz. Laboratory units runat power levels in the order of 30-50 kW while the large scaleindustrial units have been tested at power levels up to 1 MW. As theresidence time of the injected feed droplets in the plasma is very shortit is important that the droplet sizes are small enough in order toobtain complete evaporation. The RF plasma method has been used tosynthesize different nanoparticle materials, for example synthesis ofvarious ceramic nanoparticles such as oxides, carbours/carbides andnitrides of Ti and Si.

Moreover, in addition to classification by material, within eachmaterial nanoparticles may have a range of identifiable/distinctcharacteristics. For example, diamond nanoparticles, or nanodiamonds(denoted ND), have also be referred to as synthetic monocrystallinediamonds (SMD), synthetic polycrystalline diamond (SPD), utradispersediamonds (UDD), ultrananocrystalline diamond (UNCD), ultrafine diamonds(UFD), as well as naturally occurring diamonds. Nanodiamonds may includecrystalline and amorphous diamond-like materials. While SMD are preparedusing very high temperatures and pressures with the use of metalcatalysts. Other types of diamonds (SPD, UDD, UFD) are prepared with theuse of high energy explosives, such as trinitrotoluene. Xiangyang Xu,Zhiming Yu, Yongwei Zhu, Baichun Wang, Diamond & Related Materials, 14(2005) 206-212. Nicholas Tumavitch, R&D Magazine, 11 (2005) 35.Depending on the synthesis conditions, nanodiamonds can vary in size,clustering, and impurities levels. As a result, different commercialgrades of nanodiamond purity exist, as well as different methods forpurification (including oxidation employing nitric acid, or the use ofstrong acid treatments (such as hydrochloric acid)) can be performed.“Ultra Nanocrystalline Diamond: Synthesis, Properties, andApplications”, as part of Material Science and Process TechnologySeries, Edited by Olga A. Shenderova, Dieter M. Gruen, William AndrewPublishing (Norwich, N.Y.), 2006.

Nanodiamonds can be dispersed into solvents by a number of methods,including wet milling, sonication, homogenizers, and rotor statormixers. The quality and stability of a nanodiamond dispersion is verydependant on the primary or secondary solvent properties, concentrationof acids or bases, salt concentrations, surface charge (orzeta-potential) and the use of surfactant stabilizers. Xiangyang Xu,Zhiming Yu, Yongwei Zhu, Baichun Wang, Diamond & Related Materials, 14(2005) 206-212. Masaki Ozawa, Masayasu Inaguma, Makoto Takahashi,Fumiaki Kataoka, Anke Krüger, Eiji Ōsawa, Advanced Materials, 19 (2007),1201-1206.

The surface of nanodiamonds can be modified by a number of differentmanners. Oxidation, electrochemical methods, surface deposition ofmetals (e.g., palladium), and surface treatment with ammonia can be usedto modify the nanoparticle surface. To create hydrophobic nanodiamondsmaterials the use of polymeric additives (e.g., polydimethylsiloxane andpolyisoprene) or silanization reactions with trimethylsilyl groups withsurface active groups (including alcohols, amines or carboxylic acids)can be used. {“Ultra Nanocrystalline Diamond: Synthesis, Properties, andApplications”, as part of Material Science and Process TechnologySeries, Edited by Olga A. Shenderova, Dieter M. Gruen, William AndrewPublishing (Norwich, N.Y.), 2006, pages 371-374.

The hydrolytic condensation may be acid- or base-catalyzed. Inparticular embodiments, the condensation is acid-catalyzed, e.g.,wherein the acid is selected from the group consisting of hydrochloricacid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulfuricacid, formic acid, acetic acid, trichloroacetic acid, trifluoroaceticacid, and phosphoric acid. In other particular embodiments, thecondensation step is base-catalyzed, e.g., wherein the base is selectedfrom the group consisting of ammonium hydroxide, hydroxide salts of thegroup I and group II metals, carbonate and hydrogencarbonate salts ofthe group I metals, and alkoxide salts of the group I and group IImetals.

With respect to the condensation reaction, the condensation may beperformed in any solvent suitable to allow the condensation to occur inaccordance with the invention. Exemplary solvents include but are notlimited to water, methanol, ethanol, propanol, isopropanol, butanol,tert-butanol, pentanol, hexanol, cyclohexanol, hexafluoroisopropanol,cyclohexane, petroleum ethers, diethyl ether, dialkyl ethers,tetrahydrofuran, acetonitrile, ethyl acetate, pentane, hexane, heptane,benzene, toluene, xylene, N,N-dimethylformamide, dimethyl sulfoxide,1-methyl-2-pyrrolidinone, methylene chloride, chloroform, andcombinations thereof. Moreover, all of the steps of condensation may beperformed in the same reaction vessel.

The pore structure of the material may be modified by further includinga surfactant or combination of different surfactants, and by subjectingsaid material to hydrothermal treatment. Exemplary surfactants orcombinations of surfactants may be selected from the group consisting ofTriton X-45, Triton X-100, Triton X-165, Triton X-305, TLS, PluronicF-87, Pluronic P-105, Pluronic P-123, sodium dodecylsulfate (SDS),Triton X-405, tris(hydroxymethyl)aminomethane lauryl sulfate, andcombinations thereof. Additionally, the pore structure may be modifiedby utilizing the further step of addition of a porogen, including butnot limited to cyclohexanol, toluene, mesitylene, 2-ethylhexanoic acid,dibutylphthalate, 1-methyl-2-pyrrolidinone, 1-dodecanol, and TritonX-100.

In certain embodiments, the prepolymerization step involves hydrolyzingone or more components in the presence of an acid catalyst, and thecontent of organoalkoxysilane, tetraalkoxysilane, or nanoparticles(e.g., when present during the prepolymerization step) can be varied.The amount of water used for the hydrolysis can be varied (e.g., from1.1 to 1.4 mole per mole of the silane). The resulting mixture forms ahomogeneous solution, which is stirred and heated to reflux under a flowof an argon or nitrogen. After it is refluxed for a time sufficient toprepolymerize to form polyorganoalkoxysiloxane (POS), e.g.,polyalkylalkoxysiloxane, the solvent and the side product, e.g.,ethanol, is distilled off from the reaction mixture. Thereafter, theresidue is heated at an elevated temperature, e.g., in the range of 45to 85° C. under an atmosphere of an inert gas, e.g., nitrogen, argon,etc., for a period of time, e.g., 0.5 to 48 h. The residue is furtherheated at 95° C. to 120° C., e.g., for 1 to 3 h at atmospheric pressureor under reduced pressure, e.g., 10⁻²-10⁻³ torr, to remove any volatilespecies. Alternatively, the nanoparticles may be added after POSformation, with or without additional solvent, and such added solvent(if present) may or may not be removed

In particular embodiments, the next step may comprise suspending the POSinto fine beads in a solution containing water and an alcohol, such asethanol or butanol, at 45-65° C. by agitation. The volume percent ofalcohol in the solution is varied from 10 to 20%. A surfactant, such asTriton® X-100, Triton® X-165, sodium dodecylsulfate (SDS), ammoniadocecylsulfate or TRIS docecylsulfate, is added into the suspension asthe suspending agent. Without wishing to be bound by theory, thesurfactants, are believed to be able to orient at thehydrophobic/hydrophilic interface between the POS beads and the aqueousphase to stabilize the POS beads. The surfactants may also enhance theconcentration of water and the base catalyst on the surface of the POSbeads during the gelation step, through their hydrophilic groups, whichinduces the gelling of the POS beads from the surface towards thecenter. Use of surfactants to modulate the surface structure of the POSbeads may stabilize the shape of the POS beads throughout the gellingprocess and minimizes or suppresses formation of particles having anirregular shapes, e.g., “shell shaped”, and inhomogeneous morphology.

It is also possible to suspend a solution containing POS and a porogenin the aqueous phase, instead of POS alone. The porogen, which isinsoluble in the aqueous phase, remains in the POS beads during thegelation step and functions to modify the pore structure. Exemplaryporogens include, but are not limited to toluene and mesitylene. Bycontrolling the relative amount of toluene in the POS/toluene solution,the pore volume of the final hybrid particles can be more preciselycontrolled. This allows the preparation of hybrid particles having largepore volume, e.g., 0.25-1.5 cm³/g.

The gelation step may be initiated by adding a basic catalyst, e.g.,ammonium hydroxide, into the POS suspension. Thereafter, the reactionmixture is agitated to drive the reaction to completion. In certainembodiments, the basic catalyst is ammonium hydroxide or sodiumhydroxide. The particles are isolated and washed with water. Thecondensation reaction can be furthered by re-dispersing the formedhybrid particles in an aqueous acid suspension, e.g., hydrochloric acid,at reflux for 1-4 days. The thus-prepared freshmade hybrid particles arefiltered and washed with water and methanol free of ammonium ions, thendried.

The methods of preparation of the materials of the present invention mayfurther comprise the step of adding a free radical polymerizationinitiator. Exemplary free radical polymerization initiators may beselected from the group consisting of2,2′-azobis-[2-(imidazolin-2-yl)propane] dihydrochloride,2,2′-azobisisobutyronitrile, 4,4′-azobis(4-cyanovaleric acid),1,1′-azobis(cyclohexanecarbonitrile), 2,2′-azobis(2-propionamidine)dihydrochloride, 2,2′azobis(2,4-dimethylpentanenitrile),2,2′-azobis(2-methylbutanenitrile), benzoyl peroxide,2,2-bis(tert-butylperoxy)butane, 1,1-bis(tert-butylperoxy)cyclohexane,2,5-bis(tert-butylperoxy)butane,-2,5-dimethylhexane,2,5-bis(tert-butylperoxy)-2,5-dimethyl-hexyne,bis(1-(tert-butylperoxy)-1-methyethyl)benzene,1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, tert-butylhydroperoxide, tert-butyl peracetate, tert-butyl peroxide, tert-butylperoxybenzoate, tert-butylperoxy isopropyl carbonate, cumene peroxide,cyclohexanone hydroperoxide, dicumyl peroxide, lauroyl peroxide,2,4-pentanedione peroxide, peracetic acid, and potassium persulfate.Moreover, in particular embodiments, the methods of preparation mayfurther comprise the step of heating following the addition of the freeradical polymerization initiator.

In one embodiment, the pore structure of the as-prepared compositematerial is modified by hydrothermal treatment, which enlarges theopenings of the pores as well as the pore diameters, as confirmable bynitrogen (N₂) sorption analysis. The hydrothermal treatment may beperformed by preparing a slurry containing the as-prepared material anda solution of organic base in water, heating the slurry in an autoclaveat an elevated temperature, e.g., 123 to 300° C., for a period of 6 to48 h. The pH of the slurry can be adjusted to be in the range of 8.0 to12.5 using concentrated acetic acid. The concentration of the slurry isin the range of 1 g composite material per 5 to 10 ml of the basesolution. The thus-treated composite material is filtered, and washedwith water and acetone until the pH of the filtrate reaches 7, thendried at 100° C. under reduced pressure for 16 h. The resultantmaterials may show average pore diameters in the range of 30-1,000 Å.The surface of the hydrothermally treated material may be modified in asimilar fashion to that of the material that is not modified byhydrothermal treatment as described in the present invention.

The material obtained upon condensation may be further modified. Forexample, the methods of preparing the materials of the present inventionmay further comprise the step of surface modifying the material. Suchsurface modification may be achieved by the use of a surface modifierselected from the group consisting of an organic group surface modifier,a silanol group surface modifier, a polymeric coating surface modifier,e.g., Sylgard®, and combinations thereof. In certain embodiments, thesurface modifier may have the formula Z_(a)(R′)_(b)Si—R, where Z═Cl, Br,I, C₁-C₅ alkoxy, dialkylamino or trifluoromethanesulfonate; a and b areeach an integer from 0 to 3 provided that a+b=3; R′ is a C₁-C₆ straight,cyclic or branched alkyl group, and R is a functionalizing group. Inparticular embodiments, R′ is selected from the group consisting ofmethyl, ethyl, propyl, isopropyl, butyl, t-butyl, sec-butyl, pentyl,isopentyl, hexyl and cyclohexyl. In other particular embodiments, thefunctionalizing group R is selected from the group consisting of alkyl,alkenyl, alkynyl, aryl, cyano, amino, diol, nitro, ester, a cation oranion exchange group, or an alkyl or aryl group containing an embeddedpolar functionality. In one specific embodiment, the functionalizinggroup R is a C₁-C₂₀ alkyl group. Exemplary surface modifiers include,but are not limited to octyltrichlorosilane, octadecyltrichlorosilane,octyldimethylchlorosilane, and octadecyldimethylchlorosilane.

In another embodiment, the organic groups and silanol groups of thematerial are both surface modified or derivatized. In anotherembodiment, the particles are surface modified by coating with apolymer. In certain embodiments, surface modification by coating with apolymer is used in conjunction with silanol group modification, organicgroup modification, or both silanol and organic group modification.

One particular two-step polymeric surface modification of the inventionprovides a first step of bonding the surface with a silane that has aterminal alkene, epoxide(s) or some other polymerizable group, e.g.,methacryloxypropyl silanes. The second step is a polymerization of thissurface modified material. For example, bonding the surface with asilane that has a terminal epoxide, a polyvalent nucleophile (such as apolyamine) could be used to accomplish the polymerization; formethacryloxypropyl silane, free radical polymerization of organicmonomers may be used, e.g., acrylamide, allylamine, or allylalcohol(either by themselves or in mixtures).

In certain embodiments, the surface of the hydrothermally treated silicacontains organic groups, which can be derivatized by reacting with areagent that is reactive towards the particles' organic group. Forexample, vinyl groups on the particle can be reacted with a variety ofolefin reactive reagents such as bromine (Br₂), hydrogen (H₂), freeradicals, propagating polymer radical centers, dienes, and the like. Inanother example, hydroxyl groups on the particle can be reacted with avariety of alcohol reactive reagents such as isocyanates, carboxylicacids, carboxylic acid chlorides, and reactive organosilanes asdescribed below. Reactions of this type are well known in theliterature, see, e.g., March, J. “Advanced Organic Chemistry,” 3^(rd)Edition, Wiley, New York, 1985; Odian, G. “The Principles ofPolymerization,” 2^(nd) Edition, Wiley, New York, 1981; the texts ofwhich are incorporated herein by reference.

In addition, the surface of the hydrothermally treated silica alsocontains silanol groups, which can be derivatized by reacting with areactive organosilane. The surface derivatization of the hybrid silicais conducted according to standard methods, for example by reaction withoctadecyltrichlorosilane or octadecyldimethylchlorosilane in an organicsolvent under reflux conditions. An organic solvent such as toluene istypically used for this reaction. An organic base such as pyridine orimidazole is added to the reaction mixture to catalyze the reaction. Theproduct of this reaction is then washed with water, toluene and acetoneand dried at 80° C. to 100° C. under reduced pressure for 16 h. Theresultant hybrid silica can be further reacted with a short-chain silanesuch as trimethylchlorosilane to endcap the remaining silanol groups, byusing a similar procedure described above.

In another embodiment, porous particles of hybrid silica having achromatographically-enhancing pore geometry are disclosed, whereinporous hybrid silica particles are formed and the pore structure of theporous particles is modified to form hybrid silica particles having achromatographically-enhancing pore geometry. In a particular embodiment,the particles are ellipsoidal, e.g., ovoid or spherical, moreparticularly spherical. In an embodiment, a nanoparticle, anorganotrialkoxysilane and a tetraalkoxysilane are prepolymerized toproduce a polyalkyloxysiloxane; an aqueous surfactant-containingsuspension of the polyalkyloxysiloxane is prepared, and gelling in thepresence of a base catalyst is conducted so as to produce porousparticles, followed by modifying the pore structure of the porousparticles by hydrothermal treatment to produce an intermediate productwhich advantageously has other uses, and surface modifying the porousparticles. In an advantageous embodiment, the prepolymerization stepcomprises hydrolyzing and condensing a mixture of anorganotrialkoxysilane and a tetraalkoxysilane in the presence of an acidcatalyst to produce the polyalkyloxysiloxane.

In a particular embodiment, porous spherical particles of hybrid silicamay, in a particular embodiment, be prepared by a multi-step process. Inthe first step, nanoparticles, one or more organoalkoxysilanes such asbis(triethoxysilyl)ethane, and a tetraalkoxysilane such astetraethoxysilane (TEOS) are prepolymerized to form apolyorganoalkoxysiloxane (POS), e.g., polyalkylalkoxysiloxane, byco-hydrolyzing a mixture of the two or more components in the presenceof an acid catalyst (as noted herein, in certain embodiments,nanoparticles may be added to a preformed POS with or without additionalsolvent, which may or may not be followed by the removal of theadditional solvent) In the second step, the POS/nanoparticle issuspended in an aqueous medium in the presence of a surfactant or acombination of surfactants and gelled into porous spherical particles ofhybrid silica using a base catalyst. In the third step, the porestructure of the hybrid silica particles is modified by hydrothermaltreatment, producing an intermediate hybrid silica product which may beused for particular purposes itself, or desirably may be furtherprocessed below. The above three steps of the process allow much bettercontrol of the particle sphericity, morphology, pore volume and poresizes than those described in the prior art, and thus provide thechromatographically-enhancing pore geometry.

As noted above, in certain embodiments of the invention, the surfaceorganic groups of the hybrid silica are derivatized or modified in asubsequent step via formation of an organic covalent bond between theparticle's organic group and the modifying reagent. Alternatively, thesurface silanol groups of the hybrid silica are derivatized or modifiedinto siloxane functional groups, such as by reacting with anorganotrihalosilane, e.g., octadecyltrichlorosilane, or ahalopolyorganosilane, e.g., octadecyldimethylchlorosilane, or analkylaminosilane, e.g., octadecyldimethyl(dimethylamino)silane.Alternatively, the surface organic and silanol groups of the hybridsilica are both derivatized or modified. The surface of thethus-prepared material is then covered by the organic groups, e.g.,alkyl, embedded during the gelation and the organic groups added duringthe derivatization process or processes. The surface coverage by theoverall organic groups is higher than in conventional silica-basedpacking materials, and therefore the surface concentration of theremaining silanol groups in the hybrid silica is smaller. The resultingmaterial, used as a stationary phase for LC, shows excellent peak shapefor basic analytes, and better stability to alkaline mobile phases thansilica-based packing materials.

Where the prepolymerization step involves co-hydrolyzing a mixture ofthe two or more components and nanoparticles in an amount less than 20%by weight in the presence of an acid catalyst, the content of theorganoalkoxysilane, e.g., organotrialkoxysilane orbis(trialkoxysilyl)organosilane, can be varied, e.g., from about 0.03 toabout 1.0 mole per mole, or more preferably, about 0.2 to about 0.5 moleper mole, of the tetraalkoxysilane. The amount of the water used for thehydrolysis can be varied, e.g., from 1.40 to 2.20 mole per mole of thesilane. The silane, nanoparticle, water and the ethanol mixture, in theform of a homogeneous solution, is stirred and heated to reflux under aflow of argon. After it is refluxed for a time sufficient toprepolymerize to form polyorganoalkoxysiloxane (POS)/nanoparticle, e.g.,polyalkylalkoxysiloxane, the solvent and the side product, mainlyethanol, is distilled off from the reaction mixture. Thereafter, theresidue is heated at an elevated temperature, e.g., in the range of 110to 140° C. under an atmosphere of argon or nitrogen for a period oftime, e.g., 1.5 to 16 h. The residue can be further heated at thistemperature, e.g., for 1 to 3 h under reduced pressure, e.g., 10⁻²-10⁻³torr, to remove any volatile species.

In the second step, the POS/nanoparticle is suspended into fine dropletsin a solution containing water and ethanol at 55° C. by agitation. Thevolume percent of ethanol in the solution is varied from 10 to 20%. Anon-ionic surfactant such as Triton X-100, Triton X-165 or Triton X-45is added into the suspension as the suspending agent. Alternativelysodium dodecyl sulfate (SDS) or tris(hydroxymethyl)aminomethane laurylsulfate (TDS) is added into the suspension as an additional suspendingagent. The surfactants, e.g., alkylphenoxypolyethoxyethanol, arebelieved to be able to orient at the hydrophobic/hydrophilic interfacebetween the POS droplets and the aqueous phase to stabilize thePOS/nanoparticle droplets. The surfactants are also believed to enhancethe concentration of water and the base catalyst on the surface of thePOS/nanoparticle droplets during the gelation step, through theirhydrophilic groups, which induces the gelling of the POS/nanoparticledroplets from the surface towards the center. Use of surfactants tomodulate the surface structure of the POS/nanoparticle dropletsstabilizes the shape of the POS/nanoparticle droplets throughout thegelling process, and minimizes or suppresses formation of particleshaving an irregular shapes, e.g., “shell shaped”, and inhomogeneousmorphology.

It is also possible to suspend a solution containing POS/nanoparticleand porogen, e.g., toluene or mesitylene, in the aqueous phase, insteadof POS/nanoparticle alone. The toluene, which is insoluble in theaqueous phase, remains in the POS/nanoparticle droplets during thegelation step and functions as a porogen. By controlling the relativeamount of porogen in the POS/nanoparticle/porogen solution, the porevolume of the final hybrid silica can be more precisely controlled. Thisallows the preparation of hybrid silica particles having large porevolume, e.g., 0.3-1.6 cm³/g.

The gelation step is initiated by adding the basic catalyst, e.g.,ammonium hydroxide into the POS/nanoparticle suspension agitated at 55°C. Thereafter, the reaction mixture is agitated at the same temperatureto drive the reaction to completion. In a particular embodiment,ammonium hydroxide may be utilized because bases such as sodiumhydroxide are a source of unwanted cations, and ammonium hydroxide iseasier to remove in the washing step. The thus-prepared hybrid silica isfiltered and washed with water and methanol free of ammonium ions, thendried.

The present invention may also include an additional step of “sizing”the particles or selecting a range of particle size, e.g., for aparticular purpose. Any number of well known sizing techniques may beused. Such sizing techniques are described, for example, in W. Gerhartz,et al. (editors) Ullmann's Encyclopedia of Industrial Chemistry, 5thedition, Volume B2: Unit Operations I, VCH Verlagsgesellschaft mbH,(Weinheim, Fed. Rep. Germ. 1988). For example, in certain embodimentsparticles may be sized to a diameter range of about 0.5 μm to about 300μm, e.g., about 1 μm to about 20 μm.

In particular embodiments, the invention provides the followingadditional steps in the method of preparation (or such steps areutilized in the preparing the resulting products): hydrothermaltreatment, sizing, acid treatment with bonding or surface modification,or any combination thereof

The methods described herein may further comprise one or more of thefollowing steps: obtaining the nanoparticles, obtaining thepolyoligomeric organosiloxane, and/or adapting the composite materialthat is prepared for use in chromatography.

EXAMPLES

The present invention may be further illustrated by the followingnon-limiting examples describing the preparation of composite materialsof the invention, and their use.

Materials

All reagents were used as received unless otherwise noted. Those skilledin the art will recognize that equivalents of the following supplies andsuppliers exist, and as such the suppliers listed below are not to beconstrued as limiting.

Characterization

Those skilled in the art will recognize that equivalents of thefollowing instruments and suppliers exist, and as such the instrumentslisted below are not to be construed as limiting.

The % C values were measured by combustion analysis (CE-440 ElementalAnalyzer; Exeter Analytical Inc., North Chelmsford, Mass.) or byCoulometric Carbon Analyzer (modules CM5300, CM5014, UIC Inc., Joliet,Ill.). The specific surface areas (SSA), specific pore volumes (SPV) andthe average pore diameters (APD) of these materials were measured usingthe multi-point N₂ sorption method (Micromeritics ASAP 2400;Micromeritics Instruments Inc., Norcross, Ga.). The SSA was calculatedusing the BET method, the SPV was the single point value determined forP/P₀>0.98, and the APD was calculated from the desorption leg of theisotherm using the BJH method. The micropore surface area (MSA) wasdetermined as the cumulative adsorption pore diameter data for pores <34Å subtracted from the specific surface area (SSA). Particle sizes weremeasured using a Beckman Coulter Multisizer 3 analyzer (30-μm aperture,70,000 counts). The particle diameter (dp) was measured as the 50%cumulative diameter of the volume based particle size distribution. Thewidth of the distribution was measured as the 90% cumulative volumediameter divided by the 10% cumulative volume diameter (denoted 90/10ratio). Viscosity was determined for these materials using a Brookfielddigital viscometer Model DV-II (Middleboro, Mass.). Measurements of pHwere made with a Oakton pH100 Series meter (Cole-Palmer, Vernon Hills,Ill.), and were calibrated using Orion (Thermo Electron, Beverly, Mass.)pH buffered standards at ambient temperature immediately before use.Multinuclear (¹³C, ²⁹Si) CP-MAS NMR spectra were obtained using a BrukerInstruments Avance-300 spectrometer (7 mm double broadband probe). Thespinning speed was typically 5.0-6.5 kHz, recycle delay was 5 sec., andthe cross-polarization contact time was 6 msec. Reported ¹³C and ²⁹SiCP-MAS NMR spectral shifts were recorded relative to tetramethylsilaneusing the external standards adamantane (¹³C CP-MAS NMR, δ 38.55) andhexamethylcyclotrisiloxane (²⁹Si CP-MAS NMR, δ −9.62). Populations ofdifferent silicon environments were evaluated by spectral deconvolutionusing DMFit software. Massiot, D.; Fayon, F.; Capron, M.; King, I.; LeCalve, S.; Alonso, B.; Durand, J.-O.; Bujoli, B.; Gan, Z.; Hoatson, G.Magn. Reson. Chem. 2002, 40, 70-76.

Example 1 Synthesis of Polyorganosiloxanes

Following a process described by Jiang et al (U.S. Pat. No. 6,686,035B2), one or more organoalkoxysilanes or tetraalkoxysilanes (all fromGelest Inc., Morrisville, Pa. or United Chemical Technologies, INC.,Bristol, Pa.) were mixed with ethanol (EtOH, anhydrous, J.T. Baker,Phillipsburg, N.J.) in a round bottom flask. An aqueous solution 0.1 Nhydrochloric acid (Aldrich, Milwaukee, Wis.) was added drop-wise intothe flask. The resulting solution was agitated and refluxed for 16 hoursin an atmosphere of argon or nitrogen. Alcohol was removed from theflask by distillation at atmospheric pressure. Residual alcohol andvolatile species were removed by heating at 95-120° C. for 1-2 hours ina sweeping stream of argon or nitrogen. The resulting polyorganoalkoxysiloxanes were clear viscous liquids. The chemical formulas are listedin Table 1 for the organoalkoxysilanes or tetraalkoxysilanes used tomake a polyethoxylated siloxane polymer (POS). Specific amounts arelisted in Table 2 for the starting materials used to prepare theseproducts.

TABLE 1 Organoalkoxysilane A Alkoxysilane B Product Chemical FormulaChemical Formula 1 a (CH₃CH₂O)₃Si(CH₂)₂Si(OCH₂CH₃)₃ Si(OCH₂CH₃)₄ 1 b(CH₃CH₂O)₃Si(CH₂)₂Si(OCH₂CH₃)₃ —

TABLE 2 Organosilane or Organosilane Alkoxysilane 0.1N A B HCl EthanolViscosity Product (g) (g) (g) (g) % C (cP) 1a 106 250 40 218 31.6 84 1b519 0 134 653 34.7 70

Example 2 Synthesis of Polyorganosiloxanes Containing DiamondNanoparticles

Eight hundred and fifty five grams of a 4:1 molar ratio oftetraethoxysilane (TEOS, Gelest Inc., Morrisville, Pa.) and1,2-bis(triethoxysilyl)ethane (BTEE, Gelest Inc., Morrisville, Pa.) weremixed with 415 grams of ethanol (EtOH, anhydrous, J. T. Baker,Phillipsburg, N.J.) in a round bottom flask. Ninety eight grams of anaqueous solution of 2 wt % diamond nanoparticles (Warren Superabrasives,Saint-Gobain Ceramic Materials, Olyphant, Pa., 5-50 nm) in 0.1 Nhydrochloric acid (Aldrich, Milwaukee, Wis.) was prepared separately andwas added drop-wise into the flask. The resulting solution was agitatedand refluxed for 16 hours in an atmosphere of nitrogen. Alcohol wasremoved from the flask by distillation at atmospheric pressure. Residualalcohol and volatile species were removed by heating at 110° C. for 1hour in a sweeping stream of nitrogen. The resulting polyorganoalkoxysiloxane (product 2a) was an opaque mixture (viscosity=54 cP).

Example 3 Addition of Nanoparticles to Polyorganosiloxanes

Diamond nanoparticles (Nanostructured & Amorphous Materials, Inc,Houston, Tex., 4-25 nm), silicon carbide nanoparticles (Sigma-Aldrich,Saint Louis, Mo., <100 nm), or cubic boronitride (BN2600, LANDSSuperabrasives, New York, N.Y., 125 nm) were added to a POS prepared inExample 1 that contained 0-15 wt % ethanol (EtOH, anhydrous, J.T. Baker,Phillipsburg, N.J.) or 0-61 wt % mesitylene (Mes; Aldrich, Milwaukee,Wis.), to yield a 0.08-1.00 wt % dispersion. For products 3a-3e themixture was dispersed using a rotor/stator mixer (Mega Sheer, CharlesRoss & Son Co., Hauppauge, N.Y.). For product 3f a sonic probe (Sonics &Materials, Inc., Newtown, Conn.) was used. All products were centrifuged(Thermo EXD, 4×1 L bottle centrifuge, Milford, Mass.) to reduceagglomerates. The resulting products with 0.08-0.62 wt % nanoparticleincorporation were opaque mixtures. Specific amounts are listed in Table3 for the starting materials used to prepare these products.

TABLE 3 POS Nano- Pro- Pre- POS Ethanol Mesitylene Nanoparticle particleduct cursor (Kg) (L) (g) Type Mass (g) 3a 1a 9.08 — — Silicon 7.57Carbide 3b 1a 7.72 1.14 — Silicon 7.57 Carbide 3c 1a 7.72 1.14 — Silicon75.7 Carbide 3d 1a 9.08 — — Silicon 7.57 Carbide 3e 1a 9.08 — — Diamond18.60 3f 1b 0.025 — 15.53 Silicon 0.2534 Carbide 3g 1a 0.070 — — cubic-0.70 Boronitride

Example 4 Addition of Nanoparticles to Polyorganosiloxanes

Diamond nanoparticles dispersed in diethylene glycol butyl ether(UDD-K/DIOE, Warren Superabrasives, Saint-Gobain Ceramic Materials,Olyphant, Pa., 5-50 nm), diamond nanoparticles dispersed in ethanol(grade G01, agglomerate free, PlasmaChem GMBH, Berlin, Germany, 4 nm),or titanium dioxide nanoparticles dispersed in ethanol (PlasmaChem GmbH,Berlin, Germany, 15-20 nm) were added to a POS prepared in Example 1a.For products 4a-4d the flask was then heated to distill off ethanol orDIOE. Product 4a required the use of vacuum (0.5 mm Hg) and elevatedtemperatures (110-150° C.) over 20 hours to remove solvent. Products4b-4d were obtained under atmospheric conditions (80° C.) within a fewhours. For products 4e-4g the ethanol was not removed. The resultingproducts with 0.5-5 wt % nanoparticle incorporation were opaquemixtures. Specific amounts are listed in Table 4 for the startingmaterials used to prepare these products.

TABLE 4 POS POS Dispersion Product Precursor (g) Nano-dispersion Type(g) 4a 1a 100 10% Diamonds in DIOE 25 4b 1a 50 10% Diamonds in Ethanol26 4c 1a 50 10% Diamonds in Ethanol 13 4d 1a 50 10% Diamonds in Ethanol5.2 4e 1a 70 10% Diamonds in Ethanol 17.5 4f 1a 317 10% Diamonds inEthanol 19.0 4g 1a 70 5% Titanium Dioxide in Ethanol 35.0

Example 5 Synthesis of Porous Hybrid Fresh-Made Particles

a. An aqueous mixture of Triton® X-100, (Dow Chemical, Midland, Mich.),deionized water, and ethanol (EtOH; anhydrous, J.T.Baker, Phillipsburg,N.J.) was added to a round bottom flask. The aqueous solution was heatedto 55° C. for 0.5 h. In a separate flask, an oil phase solution wasprepared by mixing a mixture from Example 2, 3 or 4 for 0.5 hours withtoluene (Tol; Fisher Scientific, Suwanee, Ga.). Under rapid agitation,the oil phase mixture was added into the EtOH/water/X100 mixture and wasemulsified with the aqueous phase using a rotor/stator mixer (Model100L, Charles Ross & Son Co., Hauppauge, N.Y.). Thereafter, 30% ammoniumhydroxide (NH₄OH; J.T. Baker, Phillipsburg, N.J.) was added into theemulsion. After 20 minutes, the product was transferred to a flask andheated to 55° C. for 17 h. Formed particles in the resulting suspensionwere isolated by centrifugation (Thermo EXD, 4×1 L bottle centrifuge,Milford, Mass.) or filtration (0.5 μm filter paper) and were washedconsecutively with copious amounts of water and acetone. The particleswere dried at 80° C. under vacuum for 16 hours. Specific amounts ofstarting materials used to prepare these products are listed in Table 5.The specific surface areas (SSA), specific pore volumes (SPV) and theaverage pore diameters (APD) of these materials were measured using themulti-point N₂ sorption method and are listed in Table 5.b. An aqueous mixture of Triton® X-100 (X100, Dow Chemical, Midland,Mich.), deionized water, ethanol (EtOH; anhydrous, J.T.Baker,Phillipsburgh, N.J.), and sodium dodecyl sulfate (SDS, Sigma-Aldrich,Saint Louis, Mo.) was added to a round bottom flask. Glycolic acidethoxylate 4-tert-butylphenylether (GAS, Sigma-Aldrich, Saint Louis,Mo.) was added to adjust the pH to 5.05±0.10. The aqueous solution wasthen heated to 65° C. for 0.5 h. In a separate flask, an oil phasesolution was prepared by mixing a mixture from Example 2 or 3 for 0.5hours with toluene (Tol, Fisher Scientific, Suwanee, Ga.) or mesitylene(Mes, Aldrich, Milwaukee, Wis.). For product 5 g, since mesitylene waspreviously added to the precursor mixture 3f, additional porogen was notadded. Under rapid agitation, the oil phase solution was added into theEtOH/water/X100/SDS mixture and was emulsified with the aqueous phaseusing a rotor/stator mixer (Model 100L, Charles Ross & Son Co.,Hauppauge, N.Y.). Thereafter, one half of the 30% ammonium hydroxidesolution (NH₄OH; J.T. Baker, Phillipsburgh, N.J.) was added into theemulsion. After 20 minutes, the product was transferred to a flask andheated to 65° C. for 16 h. After 16 h, the second half of the ammoniumhydroxide solution was added and the reaction was mixed for anadditional 24 h at 65° C. Formed particles in the resulting suspensionwere isolated by centrifugation (Thermo EXD, 4×1 L bottle centrifuge,Milford, Mass.) or filtration (0.5 μm filter paper) and were washed byre-suspending the particles twice in water. The particles were thendispersed in a 1.0 M HCl solution (8.56 mL per gram particles, dry mass)and were heated to reflux for 2 days. The resulting particles wereisolated on 0.5 μm filtration paper and were washed consecutively withcopious amounts of water and acetone (HPLC grade, J.T. Baker,Phillipsburgh, N.J.). The particles were dried at 80° C. under vacuumfor 16 hours. Specific amounts of starting materials used to preparethese products are listed in Table 5. The % C values, specific surfaceareas (SSA), specific pore volumes (SPV) and average pore diameters(APD) of these materials are listed in Table 5.

TABLE 5 Estimated nano- Triton particle Pre- X- SSA SPV Incor- Pro-Nanoparticle cursor Mes Tol 100 EtOH H₂O SDS NH₄OH (m²/ (cm³/ APDporation* duct Method type Precursor (g) (g) (g) (g) (g) (g) (g) (mL) %C g) g) (Å) (wt %) 5a a Diamond 2a 58.0 — 9.7 5.6 52.0 280 — 44 7.0 5770.67 43 0.8% 5b a Diamond 2a 58.0 — 9.7 5.6 52.0 280 — 44 6.7 561 0.5638 0.8% 5c a Silicon 3d 58.0 — 9.7 5.6 52.0 280 — 44 6.8 613 0.68 400.2% Carbide 5d a Diamond 3e 58.0 — 9.7 5.6 52.0 280 — 44 6.8 618 0.6740 0.4% 5e a Diamond 3e 537.0 — 90.0 52.0 482.0 2,590 — 407 7.3 587 0.7546 0.4% 5f b Diamond 2a 23.0 14.1 — 9.3 15.0 361 0.97 46 6.6 416 1.13 970.8% 5g b Silicon 3f 25.3 — — 7.8 12.6 303 0.82 39 16.9 795 0.44 28 2.0%Carbide 5h a Diamond 4a 58.0 — 9.7 5.6 52.0 280 — 44 6.4 644 0.66 373.9% 5i a Diamond 2a 290 — 48.6 28.0 260 1400 — 220 7.12 542 0.63 420.8% 5j a Diamond 4b 44.0 — 7.4 4.2 39.4 212 — 33 12.9 622 0.52 33 9.3%5k a Diamond 4c 44.0 — 7.4 4.2 39.4 212 — 33 9.25 581 0.55 36 4.9% 5l aDiamond 4d 44.0 — 7.4 4.2 39.4 212 — 33 7.74 630 0.42 28 2.0% 5m aDiamond 4e 58.0 — 5.0 5.6 52.0 280 0.76 44 7.7 645 0.47 30 4.8% 5n aCubic- 3g 58.0 — 9.7 5.6 52.0 280 0.76 44 6.8 585 0.53 34 2.0%Boronitride 5o a Titanium 4g 58.0 — 5.0 5.6 52.0 280 0.76 44 5.9 5390.44 34 4.6% Dioxide 5p a Diamond 4f 317 — 53.0 30.6 284 1,530 4.13 2416.9 607 0.60 36 1.2% *Nanoparticle concentration estimated by assuming100% that was added in Example 1 made it into the particle aftercomplete condensation.

Example 6 Hydrothermal Processing of Porous Fresh-Made Hybrid ParticlesContaining Nanoparticles

Spherical, porous, hybrid particles containing nanoparticles fromExamples 5 were mixed with an aqueous solution of 0.3 Mtris(hydroxymethyl)aminomethane (TRIS, Aldrich Chemical, Milwaukee,Wis.) at a slurry concentration of 5 mL/g. The pH of the resultantslurry was adjusted to 9.8 using acetic acid (J.T. Baker, Phillipsburgh,N.J.). The slurry was then enclosed in a stainless steel autoclave andheated to 155° C. for 20 hours. After cooling the autoclave to roomtemperature, the product was filtered and washed thrice using water andtwice using methanol (Fisher Scientific, Suwanee, Ga.). The particleswere then dried at 80° C. under vacuum for 16 hours. Specificcharacterization data for these materials are listed in Table 6.

Selected samples were analyzed by Wide Angle X-Ray Powder Diffraction(XRPD) analysis (H&M Analytical Services, Inc. Allentown, N.J.), using aPhilips model PW1800 diffractometer (Cu radiation at 40 KV/30 mA). Scanswere run over the angular range of 10° to 60° with a step size of 0.05°and a counting time of 32 hours per sample. Under these experimentalconditions, the minimum detection level is estimated to be about 0.1%.Sample 6a exhibits evidence of a cubic SiC phase at 0.1% concentration,and sample 6f exhibits evidence of a cubic SiC phase at 1.65%concentration. These values are similar to the estimated SiCincorporation of 0.2% for 6a and 2.0% for 6f. Sample 6j exhibitedevidence of a cubic boronitride phase (19 nm). Sample 6k (FIG. 1)exhibited evidence of two polymorphs of TiO₂, Anatase (77.5% at 4.8 nm)and Brookite (22.5% at 6.6 nm).

Under these conditions, selected samples containing 0.4-3.9%nano-diamonds (≤50 nm) had no discernable peaks by XRPD. Such a resultis not unexpected, considering the low scattering intensity of diamonds(assessed by comparisons of reference intensity ratios) and the expectedbroadening of diffraction peaks with decreasing particle size(determined by the Scherrer equation, R. Jenkins, R. L. Snyder,Introduction to X-ray Powder Diffractometry; John Wiley & Sons, Inc: NewYork, N.Y., 1996). XRPD simulations of hybrid particles containingnano-diamonds less than 20 nm in size and less than 2% concentration didnot have any discernable peaks under these conditions.

TABLE 6 Estimated nanoparticle Nanoparticle SSA SPV APD MSAincorporation Product Precursor type % C (m²/g) (cm³/g) (Å) (m²/g) (wt%) 6a 5c Silicon 6.44 160 0.64 148 29 0.2% Carbide 6b 5d Diamond 6.35170 0.64 138 32 0.4% 6c 5e Diamond 6.49 187 0.70 135 25 0.4% 6d 5aDiamond 6.64 161 0.64 145 21 0.8% 6e 5b Diamond 6.39 153 0.52 122 180.8% 6f 5g Silicon 17.1 232 0.34 49 77 2.0% Carbide 6g 5h Diamond 6.71151 0.62 149 19 3.9% 6h 5i Diamond 6.72 160 0.59 133 12 0.8% 6i 5mDiamond 7.90 110 0.44 126 14 4.8% 6j 5n Cubic- 6.50 116 0.51 157 9 2.0%Boronitride 6k 5o Titanium 6.15 70 0.31 166 5 4.6% Dioxide 6l 5p Diamond6.81 120 0.57 189 16 1.2%

Example 7 Acid Treatment of Porous Hybrid Particles ContainingNanoparticles

Porous particles prepared according to Examples 6c were sized to 1.8 μm,and were then dispersed in a 1 molar hydrochloric acid solution(Aldrich, Milwaukee, Wis.) for 20 h at 98° C. The particles were thenwashed with water to a neutral pH, followed by acetone (HPLC grade, J.T.Baker, Phillipsburgh, N.J.). The particles were then dried at 80° C.under vacuum for 16 h. Specific characterization data for thesematerials are listed in Table 7. SEM characterization of 7a (FIG. 2),indicates the formation of highly spherical particles.

TABLE 7 Nano- dp₅₀ particle vol % 90/10 SSA SPV APD MSA ProductPrecursor type (μm) ratio % C (m²/g) (cm³/g) (Å) (m²/g) 7a 6c Diamond1.81 1.47 6.34 185 0.69 135 22 7b 6h Diamond 5.22 1.40 6.67 160 0.58 13214 7c 6l Diamond 2.45 1.48 6.86 123 0.55 164 18

Example 8 Initial Surface Modification of Porous Hybrid Particles withChlorosilanes

A sample from Example 7 was modified with octadecyltrichlorosilane(OTCS, Aldrich, Milwaukee, Wis.) using imidazole (Aldrich, Milwaukee,Wis.) in refluxing toluene (HPLC grade, J.T. Baker, Phillipsburgh, N.J.)for 4 hours. The reaction was then cooled and the product was filteredand washed successively with toluene, 1:1 v/v acetone/water and acetone(all solvents from J.T. Baker). The material was then refluxed in anacetone/aqueous 0.12 M ammonium acetate solution (Sigma Chemical Co.,St. Louis, Mo.) for 2 hours. The reaction was then cooled and theproduct was filtered and washed successively with toluene, 1:1 v/vacetone/water and acetone (all solvents from J.T. Baker). The productwas then dried at 80° C. under reduced pressure for 16 hours. Reactiondata is listed in Table 8. The surface concentration of C₁₈-groups wasdetermined to be 3.18 μmol/m² by the difference in particle % C beforeand after the surface modification as measured by elemental analysis.

TABLE 8 Particles OTCS Imidazole Toluene C₁₈ Coverage Product Precursor(g) (g) (g) (mL) % C (μmol/m²) 8a 7a 18 12.92 2.72 135 16.17 3.18 8b 7b10 2.48 0.87 50 14.60 2.89 8c 7c 15 2.79 0.98 150 13.34 3.00

Example 9 Secondary Surface Modification of Porous Hybrid Particles withChlorosilanes

The surface of the C₁₈-bonded hybrid material of Example 8 was furthermodified with triethylchlorosilane (TECS, Gelest Inc., Morrisville, Pa.)using imidazole (Aldrich, Milwaukee, Wis.) in refluxing toluene for 4hours. The reaction was then cooled and the product was filtered andwashed successively with water, toluene, 1:1 v/v acetone/water andacetone (all solvents from J.T. Baker) and then dried at 80° C. underreduced pressure for 16 hours. The materials were then mixed withhexamethyldisilazane (HMDS, Gelest Inc., Morrisville, Pa.) yielding aslurry (concentration 1.1 g HMDS per 1.0 g particles). The resultantslurry was then enclosed to a stainless steel autoclave and heated at200° C. for 18 hours. After the autoclave cooled to room temperature theproduct was isolated on filtration paper and washed successively withwater, toluene, 1:1 v/v acetone/water and acetone (all solvents fromJ.T. Baker) and then dried at 80° C. under reduced pressure for 16hours. Reaction data are listed in Table 9.

TABLE 9 Particles TECS Imidazole Toluene Product Precursor (g) (g) (g)(mL) % C 9a 8a 15 4.18 2.27 100 17.45 9b 8b 10 2.41 1.31 50 15.92 9c 8c14 2.53 1.37 95 14.37

Example 10 Chromatographic Evaluation of Surface Modified Porous HybridParticles

A sample of surface derivatized porous particles from Example 9 was usedfor the separation of a mixture of neutral, polar and basic compoundslisted in Table 10. The 2.1×100 mm chromatographic columns were packedusing a slurry packing technique. The chromatographic system consistedof an ACQUITY UPLC® System and an ACQUITY UPLC® Tunable UV detector.Empower 2 Chromatography Data Software (Build 2154) was used for datacollection and analysis. Mobile phase conditions were: 20 mMK₂HPO₄/KH₂PO₄, pH 7.00±0.02/methanol (36/65 v/v); flow rate: 0.25mL/min; temperature: 23.4° C.; detection: 254 nm.

It can be seen that the packing materials based on hybrid porousparticles containing nanoparticles provide ample retention andresolution in the separation of neutral, polar, and basic compounds.Relative retention is the retention time of the analyte divided by theretention time of acenaphthene. Therefore values less than one, indicateless retention than acenaphthene, and values greater than one, indicatemore retention than acenaphthene. (Relative retention is a well knownparameter in the field of HPLC.)

The comparable retention factor and relative retentions of the surfacederivatized porous particles of the present invention with respect tocommercial columns indicates that standard measurements of the utilityof the material remain relatively unchanged, while factors such asefficiency and thermal effects are improved.

TABLE 10 Relative Retention: Retention Factor: Propranolol/Butylparaben/ Naphthalene/ Dipropylphthalate/ Amitriptyline/ SampleAcenaphthene Acenaphthene Acenaphthene Acenaphthene AcenaphtheneAcenaphthene Product 9a 13.27 0.147 0.23 0.424 0.396 1.219 Product 9b11.39 0.163 0.214 0.427 0.397 1.453 Product 9c 9.32 0.153 0.229 0.4240.400 1.318 Commercial <2 μm Hybrid _(C18) Column 13.67 0.132 0.2220.420 0.403 1.240 Commercial <2 μm Silica _(C18) Column 17.90 0.1300.218 0.415 0.393 1.256 Commercial 3.5 μm Silica _(C18) Column 19.630.128 0.184 0.412 0.343 1.227 Commercial 3.5 μm Silica _(C18) Column12.57 0.181 0.283 0.439 0.525 1.839

Example 11 Peak Shape Evaluation of Surface Modified Porous HybridParticles

A sample of surface derivatized porous particles from Example 9 wereevaluated for USP peak tailing factors using the mobile phase and testconditions of Example 10. The results are shown in Table 11.

Peak tailing factors is a well known parameter in the field of HPLC (alower value corresponds to reduced tailing). It is evident that the peaktailing factors of Product 9a had comparable basic compound tailingfactors of a commercially available hybrid C₁₈-column.

The comparable tailing factors of the surface derivatized porousparticles of the present invention with respect to commercial columnsindicates that standard measurements of the utility of the materialremain relatively unchanged, while factors such as efficiency andthermal effects are improved.

TABLE 11 Tailing Factor for: Sample propranolol butylparaben naphthalenedipropylphthalate acenaphthene amitriptyline Product 9a 1.30 1.21 1.231.18 1.15 1.30 Product 9b 2.48 1.61 1.09 1.11 1.16 3.19 Product 9c 2.211.45 1.22 1.20 1.21 1.99 Commercial <2 μm Silica C₁₈ Column 0.81 1.131.05 1.11 1.02 1.41 Commercial <2 μm Hybrid C₁₈ Column 0.76 1.03 1.051.01 0.97 1.03 Commercial 3.5 μm Silica C₁₈ Column 1.37 1.15 1.07 1.081.03 2.01 Commercial 3.5 μm Silica C₁₈ Column 1.12 1.22 1.17 1.21 1.133.89

INCORPORATION BY REFERENCE

The entire contents of all patents, published patent applications andother references cited herein are hereby expressly incorporated hereinin their entireties by reference.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures described herein. Such equivalents are considered tobe within the scope of this invention and are covered by the followingclaims.

What is claimed is:
 1. A method of preparing a composite materialcomprising dispersing one or more types of nanoparticles within apolyoligomeric organosiloxane to form a dispersion mixture, andcondensing the dispersion mixture hydrolytically, such that a compositematerial is prepared, the composite material comprising a nanoparticledispersed within an inorganic or hybrid material derived from one ormore components selected from the group consisting of an organic repeatunit; an organosilyl repeat unit; and an inorganic repeat unit, whereinthe composite material is represented by the following formulaNp/(A)_(w)(B)_(x)(C)_(y) wherein: w, x, and y are each independently apositive number ranging from 0 to 1, such that w+x+y=1; Np representsthe nanoparticle, the nanoparticle comprising one or more moietiesselected from silicon carbide, diamond, cerium, carbon black, carbonnanotubes, aluminum, zirconium, barium, cobalt, copper, europium,gadolinium, iron, nickel, samarium, silver, titanium, zinc, boron,oxides thereof, and nitrides thereof; A represents the organic repeatunit; B represents the organosilyl repeat unit; C represents theinorganic repeat unit; and wherein each repeat unit is covalently bondedto one or more separate repeat units A, B, or C.
 2. The method of claim1, wherein the polyoligomeric organosiloxanes is formed from the partialcondensation of one or more components selected from the groupconsisting of an organic repeat unit; an organosilyl repeat unit; aninorganic repeat unit; and any combination thereof.
 3. The method ofclaim 1, wherein the components are selected from the group consistingof organofunctional silane, a tetraalkoxysilane, a mixture of two ormore organofunctional silanes, and a mixture of one or moreorganofunctional silanes with a tetraalkoxysilane.
 4. The method ofclaim 3, wherein the tetraalkoxysilane is tetraethoxysilane ortetramethoxysilane.
 5. The method of claim 1, wherein the organic repeatunit is incorporated into the composite material by reaction of anorganic olefin repeat unit selected from the group consisting ofdivinylbenzene, styrene, vinylbenzylchloride, ethylene glycoldimethacrylate, 1-vinyl-2-pyrrolidinone, N-vinylcaprolactam,tert-butylmethacrylate, acrylamide, methacrylamide,N,N′-(1,2-dihydroxyethylene)bisacrylamide, N,N′-ethylenebisacrylamide,N,N′-methylenebisacrylamide, butyl acrylate, ethyl acrylate, methylacrylate, 2-(acryloxy)-2-hydroxypropyl methacrylate,3-(acryloxy)-2-hydroxypropyl methacrylate, trimethylolpropanetriacrylate, trimethylolpropane ethoxylate triacrylate,tris[(2-acryloyloxy)ethyl] isocyanurate, acrylonitrile,methacrylonitrile, itaconic acid, methacrylic acid,trimethylsilylmethacrylate, N-[tris(hydroxymethyl) methyl]acrylamide,(3-acrylamidopropyl)trimethylammonium chloride,[3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxideinner salt,


6. The method of claim 1, wherein the organosilyl repeat unit isincorporated into the composite material by reaction of a functionalizedsilane selected from the group consisting of methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane,vinyltriethoxysilane, vinyltrimethoxysilane,N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyl triethoxysilane,(3-acryloxypropyl) trimethoxysilane,O-(methacryloxyethyl)-N-(triethoxysilylpropyl)urethane,N-(3-methacryloxy-2-hydroxypropyl)-3-aminopropyl triethoxysilane,methacryloxy methyltriethoxysilane, methacryloxymethyl trimethoxysilane,methacryloxypropy methyldiethoxysilane,methacryloxypropylmethyldimethoxysilane, methacryl oxypropyltris(methoxyethoxy)silane, 3-(N-styrylmethyl-2-aminoethylamino)propyltrimethoxysilane hydrochloride,

wherein each R is independently H or a C₁-C₁₀ alkyl group and wherein R′is independently H or a C₁-C₁₀ alkyl group.
 7. The method of claim 1,wherein the organosilyl repeat unit is incorporated into the compositematerial by reaction of a functionalized silane selected from the groupconsisting

wherein R is C₁-C₁₈ alkoxy, C₁-C₁₈ alkyl, or C₁-C₁₈ alkyl; R¹ is C₁-C₁₈alkoxy, C₁-C₁₈ alkyl, or C₁-C₁₈ alkyl; R² is C₁-C₁₈ alkyl, C₂-C₁₈alkenyl, C₂-C₁₈ alkynyl, C₃-C₁₈ cycloalkyl, C₁-C₁₈ heterocycloalkyl,C₅-C₁₈ aryl, or C₁-C₁₈ heteroaryl; X is C₁-C₁₈ alkoxy or C₁-C₁₈ alkyl;and n is 1-8.
 8. The method of claim 1, wherein the organosilyl repeatunit is incorporated into the composite material by reaction of afunctionalized silane selected from the group consisting ofbis(triethoxysilyl)ethane; bis(triethoxylsilyl)octane;bis(methyldiethoxysilyl)ethane; bis(triethoxysilyl)ethene;bis(trimethoxysilylethyl)benzene; ethyltriethoxysilane;diethyldiethoxysilane; mercaptopropyltriethoxysilane;methyltriethoxysilane; vinyltriethoxysilane; hexyltriethoxysilane;chloropropyltriethoxysilane; phenylethyltrimethoxysilane;octadecyltrimethoxysilane; octyltrimethoxysilane;3,3.3-trifluoropropyltrimethoxysilane; 3-cyanobutyltriethoxysilane;phenyltriethoxysilane; acetyloxyethyltrimethoxysilane;chloroethyltriethoxysilane; and fluorotriethoxysilane.
 9. The method ofclaim 1, wherein the organosilyl repeat unit is incorporated into thecomposite material by reaction of a functionalized silane:(bis(triethoxysilyl)ethane)


10. The method of claim 1, wherein the inorganic repeat unit isincorporated into the composite material by reaction of an alkoxysilaneselected from the group consisting of tetramethoxysilane,tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.
 11. Themethod of claim 1, wherein the tetraalkoxysilane is tetramethoxysilaneor tetraethoxysilane.
 12. The method of claim 1, wherein the hydrolyticcondensation is acid- or base-catalyzed.
 13. The method of claim 1,wherein the condensation is performed in a solvent selected from thegroup consisting of water, methanol, ethanol, propanol, isopropanol,butanol, tert-butanol, pentanol, hexanol, cyclohexanol,hexafluoroisopropanol, cyclohexane, petroleum ethers, diethyl ether,dialkyl ethers, tetrahydrofuran, acetonitrile, ethyl acetate, pentane,hexane, heptane, benzene, toluene, xylene, N,N-dimethylformamide,dimethyl sulfoxide, 1-methyl-2-pyrrolidinone, methylene chloride,chloroform, and combinations thereof.
 14. The method of claim 1, whereinthe composite material is in the form of particles having an averagediameter of 0.1 to 300 μm.
 15. The method of claim 1, wherein a porestructure of the composite material is modified by further including asurfactant or combination of different surfactants, and by subjectingsaid material to hydrothermal treatment.
 16. The method of claim 1,further comprising the step of surface modifying the composite material.17. The method of claim 16, wherein the composite material has beensurface modified by a surface modifier selected from the groupconsisting of an organic group surface modifier, a silanol group surfacemodifier, a polymeric coating surface modifier, and combinationsthereof.
 18. The method of claim 16, wherein the composite material hasbeen surface modified with a surface modifier having the formulaZ_(a)(R′)_(b)Si—R, where Z═Cl, Br, I, C₁-C₅ alkoxy, dialkylamino ortrifluoromethanesulfonate; a and b are each an integer from 0 to 3provided that a+b=3; R′ is a C₁-C₆ straight, cyclic or branched alkylgroup, and R is a functionalizing group.
 19. The method of claim 17,wherein the composite material has been surface modified by coating witha polymer.
 20. The method of claim 17, wherein the composite materialhas been surface modified by silanol group modification.
 21. The methodof claim 1, wherein the nanoparticle is selected from diamond, zirconiumoxide (amorphous, monoclinic, tetragonal and cubic forms), titaniumoxide (amorphous, anatase, brookite and rutile forms), aluminum(amorphous, alpha, and gamma forms), and boronitride (cubic form). 22.The method of claim 1, wherein the nanoparticle is selected from diamondand silicon carbide.